REAL TIME Dot Net Interview Question & Answer

.NET is a multi-platform software development framework provided by Microsoft. It allows the developers to build their applications across the spectrum-from web to desktop environments and even mobile and cloud environments. It supports several programming languages like C#, VB.NET, and F#, along with a rich set of libraries and tools. The framework includes some frameworks like ASP.NET, which is used for web applications, and Entity Framework for data access.

1. What is the .NET Framework?

Ans:

The .NET Framework is an integrated framework developed by Microsoft that is free of cost and provides an all-inclusive environment for application development, deployment, and execution mostly on Windows. A significant library of the .NET Framework known as the Framework Class Library of .NET Framework is very large which possesses re-usable code for commonly repeated tasks while programming.

2. What are some of the popular components of .NET?

Ans:

Some common components of the .NET Framework include the Common Language Runtime (CLR), which provides an execution environment for .NET applications, handling memory management, security, and exception handling. The Framework Class Library offers a very comprehensive library of pre-written classes and functions for developers to implement.

3. What does the JIT mean in .NET?

Ans:

• JIT stands for Just-In-Time compilation, an important process in the .NET Framework that translates MSIL code into the native machine code. 
• The positive effect of JIT compilation is the ability of the interpreter to compile only necessary code when required at runtime rather than compiling the whole application before running.
• The translation is only performed at runtime making it possible to run the code on a host computer.  There are three JIT compilers Pre-JIT, Normal JIT, and Eco JIT, and they are all intended for certain purposes.

4. What is the abbreviation MSIL?

Ans:

• MSIL is an abbreviation for, which is a low-level programming language used within the .NET Framework. It improves the abstraction between the high-level programming language and the native code.
• The intermediate, platform-independent language MSIL allows a .NET application to run on any system with a compatible CLR.
• Enhances its portability over different architectures, for instance supporting Just-In-Time compilation or runtime code optimization.

5. What is CTS?

Ans:

CTS is the short form for Common Type System. It is the core element of the .NET Framework that describes how types are declared, used, and managed in the runtime environment. It does create a set of rules and guidelines for data types, so they’re all consistent across different languages on .NET, which improves interoperability. With the use of CTS, the developers may implement applications in multiple languages while type safety and compatibility are still provided.

6. What are the key differences between COBOL and modern programming languages?

Ans:

Feature	COBOL	Modern Programming Languages
Syntax	Verbose and rigid, emphasizing readability	More concise and flexible syntax that enhances developer productivity.
Data Types	Limited to basic types (e.g., numeric, alphanumeric)	A rich variety of data types, including complex structures like collections and objects
Object-Oriented Support	Primarily procedural, with limited support for object-oriented programming	Strong support for object-oriented principles, enabling better design and code reuse
Use Cases	Mainly used in business and financial applications	Applicable across various domains, including web, mobile, and data science applications.
Performance	Optimized for batch processing and handling large data sets	Performance varies, with many languages focusing on speed and efficiency depending on the use case
Community and Support	Smaller, primarily focused on legacy systems	Large, active communities that support rapid evolution and modern development practices

7. What is. NET’s notion of ‘state management’?

Ans:

In the .NET context, state management refers to the methods adopted to preserve the state of an application across multiple requests. In a web application, where HTTP is stateless, the necessity to keep user data and preferences quite important for a seamless user experience. .NET supports several techniques for state management, including ViewState which keeps data on the page itself, and Session state, which maintains data across multiple requests for a specific user. 

8. What is CLR in .NET?

Ans:

CLR stands for Common Language Runtime. It is the central run-time component in the .NET Framework that manages the execution of .NET applications. Services provided by the CLR include memory management, garbage collection, and exception handling to keep the applications running smoothly and efficiently. CLR enforces strict security policies and grants permission to access code to protect sensitive data and resources. It also enables cross-language interoperability because code written in different .NET languages runs together seamlessly.

9. What’s the difference between managed code and unmanaged code in .NET?

Ans:

• Managed code is executed by the CLR; hence, it enjoys automatic memory management, security, and exception handling. 
• Unmanaged code is executed directly by the operating system and does not experience the management features of the CLR. 
• It employs languages, including C or C++ with unmanaged memory or does not exploit features of the managed code. 
• Managed code will provide a more secure and controlled environment than languages that employ unmanaged code.

10. What is CLS?

Ans:

• CLS is an abbreviation for Common Language Specification. CLS is a subset of CTS representing a set of rules of language interoperability within the .NET Framework. 
• The CLS will determine which features of languages in .NET are guaranteed to be available to all other languages as well, thereby implying uniform behavior and compatibility. 
• Being consistent with CLS standards allows library developers to produce libraries as well as components that could be exploited in many of the programming languages used in the .NET environment. 

11. What is the difference between System.StringBuilder and System.String?

Ans:

• System. The string is an immutable sequence of characters, which once the string is created can’t be modified later. System.
• Any modification on a string must be made by creating a new string object, which then involves overhead in performance when many modifications occur.  
• Another difference is that System.StringBuilder is mutable. It is used where the string content must be changed frequently. 

12. What does LINQ stand for?

Ans:

LINQ stands for Language Integrated Query, and it is a component of. NET. This enables developers to query different sources of data using an all-encompassing syntax directly in their programming language. It results in easier work with collections of data, such as arrays or lists, XML, and databases. Developers can write quite expressive and readable queries using C# or VB.NET and include querying capabilities directly inside the language. This reduces the need for complex SQL statements and allows compile-time checking of queries. 

13. What is an assembly in the .NET platform?

Ans:

An assembly is a basic deployment unit of the .NET Framework, which combines code, resources, and metadata in a single file representing compilation. Assemblies can be in the form of either DLL or EXE files, representing a logical group of types and resources. Assemblies enable capabilities such as versioning, security, and deployment to make CLR-managed code possible. They also carry an assembly manifest which carries information regarding the identity, version, and dependencies of assemblies.

14. What are the components of an assembly in .NET?

Ans:

An assembly in .NET is comprised of several elements, such as the assembly manifest, which includes meta-information on the assembly’s identity, version, and culture. The manifest also includes all the types and resources in the assembly, as well as any dependencies on other assemblies. Another element is the Intermediate Language (IL) code or the compiled version of the source code that the CLR executes.

15. What is caching?

Ans:

• Caching is a process of keeping frequently accessed data in a temporary storage location called cache, and improvements in application performance along with reduced data retrieval times occur. 
• In .NET, caching can be implemented at several levels application, session, and output cachin; each is used for different purposes. 
• Application caching holds the data that can be reused multiple times from different sessions, whereas session caching holds the data that is specific to a user’s session. 
• Output caching keeps the output of pages or controls, once rendered, so that there is no need to recreate these contents on subsequent requests. It cuts down on repeated data access as well as computation

16. What is the purpose of memory-mapped files in the .NET platform?

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Using memory-mapped files in .NET is a technique for sharing data among processes efficiently or accessing files on disk as though they are in memory. The key aspect is that this technique will enable large files to be mapped into the address space of an application and accessed fast, without the necessity of loading the entire file into memory. As a result, they demonstrate better performance for I/O-bound operations.

17. What does manifest mean in the .NET framework?

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The manifest in the .NET framework is assumed to be a detailed metadata file, carrying all important information about the said assembly. This includes name, version, culture, and public key token which are very crucial for an assembly’s identity and version control. The manifest is a list of all the types defined in the assembly along with their visibility and it must have references to other assemblies to ensure that all the constituent parts are available when needed at run-time.

18. How many versions of the .NET framework exist? 

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The .NET framework has evolved, and starting with its invention, the important versions released are countless. The first version, .NET Framework 1.0, was developed and released in 2002, and the core of the framework was the first solid component. In addition, 2.0, 3.0, and 3.5 introduced WPF, WCF, and LINQ. The .NET Framework 4.0 improved security and performance: it introduced the task parallel library (TPL) for asynchronous programming. The last major update is the .NET Framework 4.8, which was released in 2019 and comprises the following updates. 

19. What is the GAC?

Ans:

• The Global Assembly Cache (GAC) is a central repository in the .NET Framework that holds shared assemblies so that many applications can use the same assembly without duplication. 
• The GAC also helps make updates easier since an application can reference a new version of an assembly without having to change its code. 
• This centralization makes the shared common components easier to deploy and manage across an enterprise application. 

20. How Does .NET Support the Use of Multiple Languages? 

Ans:

The .NET framework supports multiple programming languages through the use of CLR and CTS. This means that different languages, such as C#, VB.NET, and F# are compiled into a common Intermediate Language so they can run on the same platform under the CLR. The CTS ensures that all languages share the same set of data types and behaviors to ensure that there is smooth interoperability. Developers could then always use the best language for their task, utilize libraries and components written in other languages.

21. What’s the difference between .NET Core and .NET Framework?

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.NET Core is an open-source version of the .NET framework, cross-platform. The .NET Framework has been designed by Microsoft for contemporary applications running on Windows, macOS, and Linux. In contrast, the .NET Framework is Windows-only and mainly for desktop as well as web application development, depending on the features of the Windows system. Taking performance and scalability into consideration, .NET Core appears better suited to cloud applications, as well as to microservices.

22. What is ASP.NET?

Ans:

• ASP.NET is a web application framework that runs within the .NET ecosystem for the development of dynamic web applications, services, and APIs. 
• In ASP.NET, developers can make use of either C# or VB.NET language to create strong and scalable web applications that utilize the whole power of the .NET framework. 
• With ASP.NET, the many tools and libraries that include Web Forms, MVC, and Web API can be included with the type of development needed. 
• The framework also supports features like authentication, authorization, and session management, which makes developing secure web applications much easier. 

23. How does garbage collection in .NET work?

Ans:

• Garbage collection in .NET is an automatic memory management feature that reclaims memory used by objects no longer in use. 
• During runtime, when the garbage collector or GC runs, the unreferenced objects are removed from memory, thus lowering the risk of memory leak. 
• GC is generational it categorizes objects into generations based on the lifetime that would increase performance in terms of working on short-lived objects. 
• In addition to this, the garbage collector can be manually controlled and even used for releasing unmanaged resources by implementing the IDisposable interface for that purpose.

24. What is an assembly in .NET?

Ans:

• Assemblies are the smallest units of building .NET, compiled code libraries for applications. 
• An assembly is one kind of DLL or an EXE file containing compiled code in the form of Intermediate Language (IL). 
• It also contains an assembly manifest providing metadata about its identity, version, culture, and dependencies to other assemblies. 
• Versioning is the primary use associated with an assembly so that the same piece of code can be utilized in many applications without any duplication. 

25. What is namespace in .NET?

Ans:

Namespace in .NET is the manner of organizing and grouping related classes, interfaces, and other types to avoid naming conflicts and promote code readability. A container for classes that helps developers with scope and types within an application, namespaces may be nested to allow for a hierarchical organization of code and improve its maintainability. NSpaces are generally helpful in having structured code, as they allow better organization and avoid potential conflicts.

26. How to handle exceptions in NET?

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In NET, exception handling is accomplished with try-catch-finally blocks, which enable developers to handle runtime errors gracefully. Code that possibly raises an exception is placed inside a try block, and catch blocks are used to state how to handle particular types of exceptions. If an exception has been raised, control will be transferred to the appropriate catch block, where developers may log the error, provide feedback, or try to recover. If a final block exists, it executes code that must run whether an exception was thrown such as closing resources.

27. What are delegates?

Ans:

Delegates in .NET are a type-safe function pointer, enabling methods to be passed as parameters or assigned to variables. This feature allows developers to define callback methods while still making application components more flexible and decoupling in nature. A delegate is declared with a particular signature; this is identical to the methods it can invoke, thus ensuring type safety at compile time. It also forms the basis of events in .NET, thus providing support for event-driven programming.

28. What is an event in .NET?

Ans:

• Event in .NET is a mechanism, that enables an object to communicate with other objects about specific action occurrences. 
• Events based on delegates allow methods to be attached or subscribed to the event, which allows them to be invoked when the event is raised. 
• In this respect, the event source is decoupled from the event handlers this increases loose coupling and implies flexibility. 
• Events are perhaps the most widely used type of UI programming in which an action taken by a user, is replied to appropriately by an application. 

29. How does .NET support asynchronous programming?

Ans:

• .NET supports asynchronous programming, mainly through the async and await keywords, which simplifies the development of non-blocking code very much. 
• This model is really helpful for all I/O-bound operations example, file access or web requests, in which the application would otherwise block waiting for a response. 
• The Task-based Asynchronous Pattern, short for TAP, is widely used in .NET, which allows developers to work with tasks representing ongoing operations. 
• Asynchronous programming has enhanced the scalability of web applications by allowing numerous requests to be handled since threads are not tied up.

30. What is the Common Type System? 

Ans:

The Common Type System describes how types are declared, used, and managed. NET. It allows for a set of rules that govern data types so that all languages in .NET can share and work with types in predictable ways. The CTS categorizes types into value types, such as structs, and reference types, such as classes, ensuring type safety over all languages. Imposing a common type system makes possible the interoperability of languages between C#, VB.NET, and F#.

31. What are the types of assemblies that are present in .NET?

Ans:

Assemblies in .NET can be divided into two basic types. They are private and shared assemblies. Private assemblies refer to an assembly used by a specific application. It lies in the application directory. Shared assemblies, however, are supposed to be shared among various applications and placed in the Global Assembly Cache (GAC). Based on type, each assembly type can further be categorized into various kinds: static assemblies and dynamic assemblies .

32. What is the Windows Communication Foundation (WCF)?

Ans:

Windows Communication Foundation, WCF is a framework for building service-oriented applications in .NET. WCF will enable developers to write services that could converse across different platforms and protocols for the reason of ensuring the interoperation of various systems. It utilizes various options for communication, including HTTP, TCP, and MSMQ, so that applications can be integrated at one’s discretion. Using WCF, developers can design SOAP-based as well as RESTful services to cater to the differentiated needs of different clients.

33. What is Entity Framework?

Ans:

• It reduces the effort involved in interacting with data and databases so that developers can work directly within a .NET object containing information. 
• SQL coding is not as heavily relied upon since it supports a higher abstraction over traditional data-access methods than other frameworks do. 
• Developers can use LINQ queries to work with data. It supports a good number of database providers and enables code-first, database-first, and model-first approaches in database design.

34. What is LINQ in .NET?

Ans:

• LINQ is short for Language Integrated Query, and it is the feature in .NET that enables querying of data from various sources in a consistent language-integrated syntax. 
• It allows developers to write expressive and readable queries that support querying collections, databases, and XML. There are two styles of query; namely SQL-like query syntax and method syntax, which makes use of method chaining.
• Using LINQ, developers can perform complex data manipulations and transformations directly within their code. This not only raises productivity but can also make it unnecessary to write queries using specific query languages. 

35. What are the differences between Class versus Struct in .NET?

Ans:

• The main distinction of a class versus a struct in .NET relates to memory allocation and behavior. 
• Classes are reference types because they stay on the heap, and a variable holds a reference to that object. 
• Structs, on the other hand, are value types that stay on the stack and a variable holds the actual data. 
• When assign a class instance, are copying the reference, are copying the whole value.

36. What is the IDisposable interface?

Ans:

The interface in .NET is the IDisposable. This is an interface that allows releasing unmanaged resources that are not automatically cleaned up by the garbage collector, like file handles or database connections. A class implementing IDisposable can define its cleanup logic in the Dispose method. Developers can free resources explicitly when no longer needed on such applications that are resource-intensive; this can improve the performance of an application and prevent memory leaks by timely release of resources.

37. How to implement a web service in .NET?

Ans:

To implement a web service in .NET, first define a service contract by using a specific interface or class that is decorated with appropriate attributes. For instance, while using ASP.NET Web API, will have to create a controller class whose methods handle the HTTP requests, specifying routes as well as HTTP verbs applicable for the service endpoints. May also choose to apply WCF where first define the service contracts and then implement the service interface.

38. What is the .NET Standard?

Ans:

The .NET Standard is a set of APIs that provide a uniform platform to build cross-platform applications across different implementations of .NET, such as .NET Framework, .NET Core, and Xamarin. It provides a minimum level of functionality that has to be consistent across libraries in terms of compatibility and reusability in several .NET environments. This supports code sharing and simplifies the development for applications supporting multi-platforms.

39. What is the Model-View-Controller (MVC) pattern in ASP.NET?

Ans:

• The Model-View-Controller (MVC) pattern is one kind of architectural design pattern utilized in ASP.NET. The application is divided into three primary components: Model, View, and Controller. 
• This model represents the data and business logic of an application, which also manages data and state. The view serves the purpose of rendering a user interface and it handles user interactions. 
• The controller plays an intermediary role between the model and the view. Taking input, manipulating the model, and updating the view based on the new input conditions are some of the functions of this layer. 

40. What is the Common Type System? 

Ans:

• The Common Type System describes how types are declared, used, and managed. NET. Imposing a common type system makes possible the interoperability of languages between C#, VB.NET, and F#.
• It allows for a set of rules that govern data types so that all languages in .NET can share and work with types in predictable ways. 
• The CTS categorizes types into value types, such as structs, and reference types, such as classes, ensuring type safety over all languages.

41. What are the types of assemblies that are present in .NET?

Ans:

• Assemblies in .NET can be divided into two basic types. They are private and shared assemblies. 
• Private assemblies refer to an assembly used by a specific application. It lies in the application directory. 
• Shared assemblies, however, are supposed to be shared among various applications and placed in the Global Assembly Cache (GAC). 
• Knowing these types would help manage the dependencies and deployment of .NET applications.

42. What is the Windows Communication Foundation (WCF)?

Ans:

Windows Communication Foundation, WCF is a framework for building service-oriented applications in .NET. WCF will enable developers to write services that could converse across different platforms and protocols for the reason of ensuring the interoperation of various systems. It utilizes various options for communication, including HTTP, TCP, and MSMQ, so that applications can be integrated at one’s discretion.Using WCF, developers can design SOAP-based as well as RESTful services to cater to the differentiated needs of different clients.

43. What is Entity Framework?

Ans:

Entity Framework is an Object-Relational Mapping (ORM) framework designed for. NET. It reduces the effort involved in interacting with data and databases so that developers can work directly within a .NET object containing information. SQL coding is not as heavily relied upon since it supports a higher abstraction over traditional data-access methods than other frameworks do. Developers can use LINQ queries to work with data. 

44. What is LINQ in .NET?

Ans:

LINQ is short for Language Integrated Query, and it is the feature in .NET that enables querying of data from various sources in a consistent language-integrated syntax. In other words, it allows developers to write expressive and readable queries that support querying collections, databases, and XML. There are two styles of query; namely SQL-like query syntax and method syntax, which makes use of method chaining. This not only raises productivity but can also make it unnecessary to write queries using specific query languages.

45. What are the differences between Class versus Struct in .NET?

Ans:

• The main distinction of a class versus a struct in .NET relates to memory allocation and behavior.  Structs, on the other hand, are value types that stay on the stack and a variable holds the actual data. 
• These differences lead to different behaviors regarding copying, when assign a class instance, when assign a struct instance, are copying the whole value. 
• Classes can also be used to add further support for inheritance; thus, a struct can’t, as a programmer, inherit from another struct or class. 

46. What is the IDisposable interface?

Ans:

• The interface in .NET is the IDisposable. This is an interface that allows releasing unmanaged resources that are not automatically cleaned up by the garbage collector.
• Developers can free resources explicitly when no longer needed on such applications that are resource-intensive; this can improve the performance of an application and prevent memory leaks by timely release of resources.
• If it uses a statement with an object that implements IDisposable, even if an exception occurs, Dispose is called automatically.

47. How to implement a web service in .NET?

Ans:

• To implement a web service in .NET, first define a service contract by using a specific interface or class that is decorated with appropriate attributes. 
• May also choose to apply WCF where first define the service contracts and then implement the service interface. Then go ahead and deploy service in a web server or cloud environment.
• The steps for designing a web service using .NET are, by no means, very challenging and, again, still largely dependent upon the capabilities of the framework in web development.

48. What is the .NET Standard?

Ans:

The .NET Standard is a set of APIs that provide a uniform platform to build cross-platform applications across different implementations of .NET, such as .NET Framework, .NET Core, and Xamarin. It provides a minimum level of functionality that has to be consistent across libraries in terms of compatibility and reusability in several .NET environments. The ability to target .NET Standard permits library developers to code libraries that will work well across different platforms, easy to manage since they no longer have to control multiple code bases. 

49. What is the Model-View-Controller (MVC) pattern in ASP.NET?

Ans:

The Model-View-Controller (MVC) pattern is one kind of architectural design pattern utilized in ASP.NET. The application is divided into three primary components: Model, View, and Controller. This model represents the data and business logic of an application, which also manages data and state. The view serves the purpose of rendering a user interface it is a display of data that could be forwarded to the user, and it handles user interactions. The controller plays an intermediary role between the model and the view.

50. How does managed code run in the .NET framework?

Ans:

The three-step process of running in the context of the .NET framework starts with compilation to execute the managed code. At the time of building a .NET application, it gets compiled into MSIL which is independent of the platform. It is CLR that takes control during runtime and converts MSIL to native machine code and completes the job by JIT compilation. The CLR touches upon a multitude of services about memory allocation, garbage collection, security, and more, ensuring a safe execution environment. 

51. What is SignalR in .NET?

Ans:

• SignalR is a library for ASP.NET that simplifies real-time web functionality to applications.
• SignalR abstracts away the complexity of multiple transport protocols – WebSockets, Server-Sent Events, etc. along with automatic selection of the best available option. 
• This helps developers integrate SignalR easily into their existing ASP.NET applications. In a nutshell, SignalR brings interactivity and responsiveness to web applications.

52. What are some of the types of web applications can build with .NET?

Ans:

• Can build several types of web applications using. NET. Building ASP.NET MVC applications allows to have rich interactive user experiences. 
• ASP.Net Web Forms comes with an event-driven model to develop dynamic web pages. ASP.NET Core supports both cross-platform web APIs and server-side-rendered applications. 
• With these, can also build single-page applications (SPAs) with Angular or React, taking advantage of ASP.NET for SPAs.  With the help of Blazor, can now create interactive web UIs using C# instead of JavaScript.

53. What is middleware in ASP.NET Core?

Ans:

• Middleware in ASP.NET Core is the software assembled into an application pipeline to handle requests and responses. 
• Each component can process incoming requests, perform actions, and pass control to the next middleware of the pipeline. 
• It can handle cross-cutting concerns such as logging, authentication, and error handling. 
• The order of middleware in the pipeline is very significant because this decides how the requests will be processed.

54. How to implement security in an ASP.NET application?

Ans:

Implementation of security in an ASP.NET application incorporates layers like authentication, authorization, and protection of data. ASP.NET Identity is the framework encapsulating the user authentication and management of roles.Can make use of cookie authentication or JWT tokens, which come as a feature, to have user sessions securely. Authorization policy makes an impact on the system for controlling access to resources depending upon the roles or claims of a user.

55. What is the term virtual method in .NET?

Ans:

A virtual method in .NET is defined within a base class and can be overridden in the derived classes. In other words, it allows for polymorphism that makes it possible for a derived class to provide its specific implementation of a method. By declaring a method virtual, the derived class is allowed to change its behavior using the override keyword. If a subclass does not override a virtual method then by default, the subclass inherits the base class’s implementation for that method. The use of virtual methods provides runtime method binding, which enables flexible code.

56. What does boxing and unboxing refer to in .NET?

Ans:

Boxing in .NET is the operation of changing a value type (like int, char) into an object type or to a nullable type; this requires encapsulating the value in an object. In this way, value types can be used like reference types so they can be held within collections that require objects. The reverse operation is called unboxing. Unboxing converts the object back to its original type before boxing. Although boxing is flexible, it has a performance overhead due to memory allocation for the object. 

57. What is a thread pool?

Ans:

A set of reusable threads managed by CLR to handle multiple tasks efficiently. The thread pool maintains pools of pre-allocated, idle threads, ready to use, so the application doesn’t need to pay the price of reallocation for each task-it’s created and destroyed. This means that while a task is submitted, it is run by a thread from the pool, which will help improve the application’s performance as well as resource utilization. It adjusts, based on demand, how many active threads are present at any time.

58. How to unit test in .NET?

Ans:

• To unit test in .NET, may use a testing framework such as MSTest, NUnit, or xUnit.
• Unit tests are developed methods where developers test small units of code against expected behavior. 
• Test projects are created together with the main application that the test project references, so can test classes. 
• The framework provides attributes to define test cases and methods to make assertions on the expected outcome. 
• Tools such as Visual Studio offer integrated testing support, including the ability to run tests and view results. 

59. What are generics in .NET?

Ans:

• Generics in .NET allow programmers to write classes, interfaces, and methods with a placeholder for the data type, enhancing the reusability of code as well as its type safety. 
• Using generics will be able to create collections and data structures that work with any kind of data without losing performance. 
• Generics help to avoid boxing and unboxing when using value types, which reduces efficiency. Compiling time checking for generic types also reduces runtime errors. 
• Common examples include List<T>, Dictionary<TKey, TValue>, and other collection classes.

60. What is the purpose of the Global Sax file?

Ans:

The Global. Sax is an ASP.NET file that holds application-level event handlers and logic. It provides a point where developers may listen for events in their application’s lifecycle. The code can go into this file, initializing some settings of the application, configuring services, or even application-wide error handling. Global. Sax allows for centralized management of application behavior, as well as allowing the registration of routes and services within an application as it starts to play a crucial role in managing the lifecycle and behavior of an application.

61. How is caching implemented in ASP.NET?

Ans:

There are various methods of caching applications in ASP.NET. In-cache can either be in-memory, distributed, or output cache. In terms of MemoryCache, let a certain amount of data remain in memory to speed things up. Can set an expiration policy; the items get automatically removed from the cache. This is output-caching where it saves the rendered HTML output of the page; hence it reduces processing time because would be rendering the page once and then have a copy to use next time.

62. What is a configuration file in .NET?

Ans:

A configuration file in .NET typically is web. Config for web applications and app. config for desktop applications. These contain application settings, connection strings, and other configurable parameters. In the XML format, configuration files are written, and one does not have to recompile the application when changing settings; instead, configuration file values can be retrieved and used at runtime with the help of the ConfigurationManager class.

63. How to connect to a database in .NET?

Ans:

• Use ADO.NET when connecting to any database in .NET; it contains classes like SqlConnection, SqlCommand, and SqlDataReader. 
• Begin by creating a connection string that says where database is located and everything concerning credentials.  Create a SqlConnection object based on that string by opening the connection. 
• With a SqlCommand can execute SQL queries or stored procedures.Data can be read using SqlDataReader or filled into a DataSet.
• Don’t forget to handle connections correctly using the statements to ensure automatic disposal.

64. What is ADO.NET?

Ans:

• ADO.NET is a part of the .NET Framework classes that permits developers to access and manipulate data coming from a wide range of sources like SQL Server, Oracle, and XML. 
• It offers two critical components the DataSet, a representing cache for in-memory data, and the DataReader, offering high-performance, read-only access to data from a data source. 
• ADO.NET supports disconnected architecture; therefore, an application can work with the data while keeping resource utilization minimum. It also includes transaction support and can interact with data that falls within the XML format.

65. What are the differences between IEnumerable and IQueryable?

Ans:

• IEnumerable is used for collections that can be enumerated forward only. It is an in-memory object and therefore quite useful for the collection that lives only in memory. 
• It is the opposite of IQueryable and is typically used for querying data from a data source LINQ typically uses a database. It supports deferred execution; that is, the query is only executed when it is needed. 
• This class will optimize the query by translating it into SQL, whereas IEnumerable will execute a query in memory. Use the IQueryable class for database queries and IEnumerable for in-memory collections.

66. What is a background worker in .NET?

Ans:

The BackgroundWorker class in .NET provides a means to run operations on a separate, dedicated thread. This is particularly useful for time-consuming tasks that should not block the main UI thread, which improves application responsiveness. It also has some support for cancellation and progress reporting, so the UI can update as the operation progresses. It is often used in Windows Forms applications for tasks like file processing or network operations.

67. What is Cross-Origin Resource Sharing (.NET)?

Ans:

CORS is an online security feature implemented within a web browser it will determine whether to provide the resource or deny the request for access based on a different origin from where the web page was served. In .NET, can configure the CORS to allow certain domains to access resources. Here’s how can implement CORS in ASP.NET application using the Microsoft.AspNetCore.Cors package, configured in Startup. Cs file. This calls for the definition of policies that detail allowed origins, methods, and headers.

68. How would implement authentication within an ASP.NET application?

Ans:

Authentication within an ASP.NET application can be implemented using built-in capabilities such as Forms Authentication, Windows Authentication, or ASP.NET Identity. For Forms Authentication, create a login page that validates user credentials and will issue a cookie to control the session. ASP.NET Identity provides a more comprehensive solution to user management, which includes roles and claims. Most of this configuration will occur in the Startup.cs file when working with authentication schemes and policies.

69. What are web forms in ASP.NET?

Ans:

• Web Forms is a framework in ASP.NET for dynamic web applications. It is a page-based model: developers could create web pages by using both HTML as well as server-side controls. 
• Each control encapsulates rendering as well as state management, which makes the development easier. Web Forms supports event-driven programming, meaning developers can respond to client events.
• While it does offer rapid development, many of today’s modern applications prefer using ASP.NET MVC or ASP.NET Core for the added control and flexibility.

70. What does the HttpContext class?

Ans:

The class HttpContext in ASP.NET captures every HTTP-related information concerning one HTTP request. It gives access to request and response data such as headers, query strings, and form data. Developers make use of HttpContext to manage session state, cookies, and application state. It serves as the connecting link between the web server and an ASP.NET application, making it possible to read and alter the data for the request/response that occurs as part of the lifecycle of a request. 

71. How to maintain state in ASP.NET?

Ans:

State management in ASP.NET is the process of holding information between multiple requests. ASP.NET provides several options for state management. View State maintains data on the client side between postbacks. Session State preserves user information on the server for the entire session, and Application State is applied to any data shared by all users. Another thing could do is use cookies to store small pieces of information unique to the user. Again, that depends on the nature of application being scalable, secure, and performant.

72. What are the types of sessions in .NET?

Ans:

• Sessions can be managed in .NET in the following ways: In-Process Session is storing session information in memory on the web server, where it has access speed but not scalability.
• Data will be stored in a different process, which permits out-of-process storage and supports scalability. SQL Server Session Session data will exist in a database, which supports durability and allows web farms. 
• Custom Session Providers can be created depending on the special storage needs. All the options have trade-offs related to performance, scalability, and complexity.

73. What is the difference between ViewBag and ViewData?

Ans:

• ViewBag and ViewData are two different methods that can be used to pass information from a controller to a view in ASP.NET MVC. 
• The only difference is that ViewData is a dictionary object that stores key-value pairs and have to typecast while extracting values. 
• ViewBag is a dynamic property. It means that the developer has to typecast nothing to access data, which makes it more developer-friendly. 
• It all depends on a dynamic type of keyword, which will lead to runtime errors if keywords are misspelled.

74. How to implement logging in a .NET application?

Ans:

Can implement logging in a .NET application using a few different frameworks, the most popular of which are Serilog, NLog, and log4net. Begin by installing a logging framework via NuGet and then doing some configuration within an application’s startup. It is possible to configure the targets for where the logs are output to include files, databases, or cloud services. Then inject the logger into classes using dependency injection. Proper logging involves logging levels, such as Info, Warn, and Error, which group messages.

75. What is the Service Locator pattern?

Ans:

The Service Locator pattern is one of the design patterns that retrieve an application’s dependency. It can be considered as a central registry issuing access to multiple services without the classes containing information about their implementation. It promotes loose coupling and makes testing easier since object creation is detached from classes that use the services. At the same time, it introduces hidden dependencies and obfuscates code.

76. What is LINQ query syntax?

Ans:

• LINQ query syntax is a way to access data from collections or databases directly within C# using a SQL-like syntax. Write queries against arrays, lists, or databases using keywords such as from, where select, and orderly. 
• Because this syntax reads more like SQL, it’s much easier to read than normal Linq with the same static type checking and IntelliSense available. 
• This is made easy and expressive because LINQ query syntax supports filtering, grouping, and sorting operations.

77. What is a data context in Entity Framework?

Ans:

• A data context in Entity Framework will act as a bridge between the application and the database that manages the connection and assists in CRUD operations. 
• The context based on changes to entities makes it possible to retrieve data efficiently and update it in real time. 
• When creating a service application using Entity Framework Code First, the data context defines how entity classes are mapped to database tables. 
• Developers would often encapsulate database logic and configurations within a class that inherits DbContext.

78. How can establish a RESTful service in .NET?

Ans:

• Building a web API of a RESTful service can be done on top of the ASP.NET core, starting with defining a controller class that extends ControllerBase. 
• Then use attributes like [HttpGet], [HttpPost], [HttpPut], and [HttpDelete] to define the endpoints and their corresponding HTTP methods. 
• The routing configuration inside Startup.cs tells ASP.NET how requests should map to controllers.  Ensure API endpoints are protected with the appropriate authentication and authorization.

79. What does a controller do in MVC?

Ans:

A Controller in the MVC (Model-View-Controller) pattern acts as a middleman between the Model and the View. The controller accepts user input, processes requests, and changes data through interaction with the Model. After processing, the controller will determine which View to return as the response. Controllers are also responsible for controlling the flow of the application. They include validation of the input and implementing the business logic.

80. What is middleware in ASP.NET Core?

Ans:

Middleware in ASP.NET Core is a piece of software that executes each request to an application. What it does is handle requests and responses, and thus it can be used in adding custom processing logic, such as authentication and loggùng as well as error handling. Middleware can be configured between lines in the Startup.cs file in the Configure method where can define the order of execution of components. Each middleware can either short-circuit the request pipeline or pass control to the next middleware.

81. How to handle file uploads in ASP.NET?

Ans:

In an ASP.NET Core application, would typically use the IFormFile interface to handle file uploads in ASP.NET. First, would create a form in HTML containing an <input type=”file”> element for this purpose. In the controller, might have an action where it accepts the uploaded file as a parameter. To save the file to an appointed directory, methods like FileStream or CopyToAsync would be used. Validate file types and sizes for security reasons. Consider also some use of middleware for handling greater uploads.

82. What does HttpClient do?

Ans:

• HttpClient is a class in the .NET Framework that facilitates the sending of an HTTP request and reception of an HTTP response from a resource identified by a URI. 
• HttpClient is ideal for calling RESTful services or APIs because it takes care of anything requiring headers in request, query parameters, and content. 
• This supports modern features like cancellation tokens and automatic handling of cookies. To avoid socket exhaustion, instantiate HttpClient once and reuse it throughout the application.

83. What are the advantages of Azure? NET.

Ans:

• There are lots of advantages to using Azure with .NET including scalability, security, and integrations of other Microsoft services. 
• Having Azure App Services, Azure Functions, and Azure SQL Database, among many more cloud services, it can be easily deployed by developers. 
• The system has also supported seamless DevOps practices using tools such as Azure DevOps, and GitHub Actions. 
• With the global infrastructure of Azure, applications may be deployed closer to users thereby improving performance. 

84. What is ASP.NET? How do implement role-based security in ASP.NET?

Ans:

• Role-based security on an ASP.NET application is usually implemented by using ASP.NET Identity. 
• The RoleManager would be used for the creation and management of those roles, while the UserManager can be used to assign users to roles. 
• The following attribute would be used within controllers or action methods to restrict access based on the user’s role.
• Also, include the role management in the Startup.cs file. This way, specific resources could not be accessed without proper authorization.

85. What is dependency inversion in .NET?

Ans:

Dependency inversion refers to the software design principle that says that high-level modules should depend on abstractions rather than concrete implementations. In the context of .NET, this can very often be fulfilled through interfaces or abstract classes, which are much more flexible and easier to test. Can replace the implementations without modifying the high-level code by inverting dependencies.

86. How to raise custom exceptions in .NET?

Ans:

To raise custom exceptions in .NET, might inherit a new exception class from the base Exception class. Can extend it further with more properties or methods to add further details about the error. Can surround application code with a try-catch block to catch the custom exception and allow for some form of graceful error handling. The user can use a logging framework to log the details of the exception.

87. How does it relate to a partial class in .NET?

Ans:

A partial class in .NET is a way of breaking the definition of a class into pieces spread across multiple files. It is also useful to organize large classes or to separate auto-generated code, such as designer files from code developed by the developer. All parts must include the keyword and be contained in the same namespace. The compiler will combine all parts into a single class during the compilation of the application.

88. How will handle application configuration settings in .NET?

Ans:

• Application configuration in .NET can be controlled by appsettings.json files in ASP.NET Core or the use of the web. 
• Config in traditional ASP.NET applications; both these store key connection strings or application-specific settings in the form of a list of key-value pairs. 
• Can use the IConfiguration interface to access application settings in ASP.NET Core.  It supports multiple sources, including JSON files, environment variables, and command-line arguments.

89. What is the role of the Task Parallel Library of .NET?

Ans:

• The Task Parallel Library, abbreviated TPL, is a .NET class library that provides public types and APIs for parallel programming. 
• Utilizing the TPL gives a strong framework for the asynchronous and parallel management of tasks to write more efficient and scalable applications. 
• TPL provides the Task class for representing an asynchronous operation and is complemented with methods, used for creating, scheduling, and managing tasks. 
• It supports parallel loops and LINQ queries for data processing. Developers can also use TPL to improve the responsiveness of an application, as well as optimize available system resources.

90. How to implement OAuth authentication in an ASP.NET application?

Ans:

Implement OAuth authentication have the choice of configuring an ASP.NET application with external authentication providers such as Google, Facebook, or Microsoft. In ASP .NET Core.OAuth package. First, need to register authentication services in Startup. Cs. Inside it, specify the client ID and secret of the provider. Implement callback methods as necessary to address authentication and get user information.

1. What is the .NET Framework?

Ans:

The .NET Framework is an integrated framework developed by Microsoft that is free of cost and provides an all-inclusive environment for application development, deployment, and execution mostly on Windows. A significant library of the .NET Framework known as the Framework Class Library of .NET Framework is very large which possesses re-usable code for commonly repeated tasks while programming.

2. What are some of the popular components of .NET?

Ans:

Some common components of the .NET Framework include the Common Language Runtime (CLR), which provides an execution environment for .NET applications, handling memory management, security, and exception handling. The Framework Class Library offers a very comprehensive library of pre-written classes and functions for developers to implement.

3. What does the JIT mean in .NET?

Ans:

• JIT stands for Just-In-Time compilation, an important process in the .NET Framework that translates MSIL code into the native machine code. 
• The positive effect of JIT compilation is the ability of the interpreter to compile only necessary code when required at runtime rather than compiling the whole application before running.
• The translation is only performed at runtime making it possible to run the code on a host computer.  There are three JIT compilers Pre-JIT, Normal JIT, and Eco JIT, and they are all intended for certain purposes.

4. What is the abbreviation MSIL?

Ans:

• MSIL is an abbreviation for, which is a low-level programming language used within the .NET Framework. It improves the abstraction between the high-level programming language and the native code.
• The intermediate, platform-independent language MSIL allows a .NET application to run on any system with a compatible CLR.
• Enhances its portability over different architectures, for instance supporting Just-In-Time compilation or runtime code optimization.

5. What is CTS?

Ans:

CTS is the short form for Common Type System. It is the core element of the .NET Framework that describes how types are declared, used, and managed in the runtime environment. It does create a set of rules and guidelines for data types, so they’re all consistent across different languages on .NET, which improves interoperability. With the use of CTS, the developers may implement applications in multiple languages while type safety and compatibility are still provided.

6. What are the key differences between COBOL and modern programming languages?

Ans:

Feature	COBOL	Modern Programming Languages
Syntax	Verbose and rigid, emphasizing readability	More concise and flexible syntax that enhances developer productivity.
Data Types	Limited to basic types (e.g., numeric, alphanumeric)	A rich variety of data types, including complex structures like collections and objects
Object-Oriented Support	Primarily procedural, with limited support for object-oriented programming	Strong support for object-oriented principles, enabling better design and code reuse
Use Cases	Mainly used in business and financial applications	Applicable across various domains, including web, mobile, and data science applications.
Performance	Optimized for batch processing and handling large data sets	Performance varies, with many languages focusing on speed and efficiency depending on the use case
Community and Support	Smaller, primarily focused on legacy systems	Large, active communities that support rapid evolution and modern development practices

7. What is. NET’s notion of ‘state management’?

Ans:

In the .NET context, state management refers to the methods adopted to preserve the state of an application across multiple requests. In a web application, where HTTP is stateless, the necessity to keep user data and preferences quite important for a seamless user experience. .NET supports several techniques for state management, including ViewState which keeps data on the page itself, and Session state, which maintains data across multiple requests for a specific user. 

8. What is CLR in .NET?

Ans:

CLR stands for Common Language Runtime. It is the central run-time component in the .NET Framework that manages the execution of .NET applications. Services provided by the CLR include memory management, garbage collection, and exception handling to keep the applications running smoothly and efficiently. CLR enforces strict security policies and grants permission to access code to protect sensitive data and resources. It also enables cross-language interoperability because code written in different .NET languages runs together seamlessly.

9. What’s the difference between managed code and unmanaged code in .NET?

Ans:

• Managed code is executed by the CLR; hence, it enjoys automatic memory management, security, and exception handling. 
• Unmanaged code is executed directly by the operating system and does not experience the management features of the CLR. 
• It employs languages, including C or C++ with unmanaged memory or does not exploit features of the managed code. 
• Managed code will provide a more secure and controlled environment than languages that employ unmanaged code.

10. What is CLS?

Ans:

• CLS is an abbreviation for Common Language Specification. CLS is a subset of CTS representing a set of rules of language interoperability within the .NET Framework. 
• The CLS will determine which features of languages in .NET are guaranteed to be available to all other languages as well, thereby implying uniform behavior and compatibility. 
• Being consistent with CLS standards allows library developers to produce libraries as well as components that could be exploited in many of the programming languages used in the .NET environment. 

11. What is the difference between System.StringBuilder and System.String?

Ans:

• System. The string is an immutable sequence of characters, which once the string is created can’t be modified later. System.
• Any modification on a string must be made by creating a new string object, which then involves overhead in performance when many modifications occur.  
• Another difference is that System.StringBuilder is mutable. It is used where the string content must be changed frequently. 

12. What does LINQ stand for?

Ans:

LINQ stands for Language Integrated Query, and it is a component of. NET. This enables developers to query different sources of data using an all-encompassing syntax directly in their programming language. It results in easier work with collections of data, such as arrays or lists, XML, and databases. Developers can write quite expressive and readable queries using C# or VB.NET and include querying capabilities directly inside the language. This reduces the need for complex SQL statements and allows compile-time checking of queries. 

13. What is an assembly in the .NET platform?

Ans:

An assembly is a basic deployment unit of the .NET Framework, which combines code, resources, and metadata in a single file representing compilation. Assemblies can be in the form of either DLL or EXE files, representing a logical group of types and resources. Assemblies enable capabilities such as versioning, security, and deployment to make CLR-managed code possible. They also carry an assembly manifest which carries information regarding the identity, version, and dependencies of assemblies.

14. What are the components of an assembly in .NET?

Ans:

An assembly in .NET is comprised of several elements, such as the assembly manifest, which includes meta-information on the assembly’s identity, version, and culture. The manifest also includes all the types and resources in the assembly, as well as any dependencies on other assemblies. Another element is the Intermediate Language (IL) code or the compiled version of the source code that the CLR executes.

15. What is caching?

Ans:

• Caching is a process of keeping frequently accessed data in a temporary storage location called cache, and improvements in application performance along with reduced data retrieval times occur. 
• In .NET, caching can be implemented at several levels application, session, and output cachin; each is used for different purposes. 
• Application caching holds the data that can be reused multiple times from different sessions, whereas session caching holds the data that is specific to a user’s session. 
• Output caching keeps the output of pages or controls, once rendered, so that there is no need to recreate these contents on subsequent requests. It cuts down on repeated data access as well as computation

16. What is the purpose of memory-mapped files in the .NET platform?

Ans:

Using memory-mapped files in .NET is a technique for sharing data among processes efficiently or accessing files on disk as though they are in memory. The key aspect is that this technique will enable large files to be mapped into the address space of an application and accessed fast, without the necessity of loading the entire file into memory. As a result, they demonstrate better performance for I/O-bound operations.

17. What does manifest mean in the .NET framework?

Ans:

The manifest in the .NET framework is assumed to be a detailed metadata file, carrying all important information about the said assembly. This includes name, version, culture, and public key token which are very crucial for an assembly’s identity and version control. The manifest is a list of all the types defined in the assembly along with their visibility and it must have references to other assemblies to ensure that all the constituent parts are available when needed at run-time.

18. How many versions of the .NET framework exist? 

Ans:

The .NET framework has evolved, and starting with its invention, the important versions released are countless. The first version, .NET Framework 1.0, was developed and released in 2002, and the core of the framework was the first solid component. In addition, 2.0, 3.0, and 3.5 introduced WPF, WCF, and LINQ. The .NET Framework 4.0 improved security and performance: it introduced the task parallel library (TPL) for asynchronous programming. The last major update is the .NET Framework 4.8, which was released in 2019 and comprises the following updates. 

19. What is the GAC?

Ans:

• The Global Assembly Cache (GAC) is a central repository in the .NET Framework that holds shared assemblies so that many applications can use the same assembly without duplication. 
• The GAC also helps make updates easier since an application can reference a new version of an assembly without having to change its code. 
• This centralization makes the shared common components easier to deploy and manage across an enterprise application. 

20. How Does .NET Support the Use of Multiple Languages? 

Ans:

The .NET framework supports multiple programming languages through the use of CLR and CTS. This means that different languages, such as C#, VB.NET, and F# are compiled into a common Intermediate Language so they can run on the same platform under the CLR. The CTS ensures that all languages share the same set of data types and behaviors to ensure that there is smooth interoperability. Developers could then always use the best language for their task, utilize libraries and components written in other languages.

21. What’s the difference between .NET Core and .NET Framework?

Ans:

.NET Core is an open-source version of the .NET framework, cross-platform. The .NET Framework has been designed by Microsoft for contemporary applications running on Windows, macOS, and Linux. In contrast, the .NET Framework is Windows-only and mainly for desktop as well as web application development, depending on the features of the Windows system. Taking performance and scalability into consideration, .NET Core appears better suited to cloud applications, as well as to microservices.

22. What is ASP.NET?

Ans:

• ASP.NET is a web application framework that runs within the .NET ecosystem for the development of dynamic web applications, services, and APIs. 
• In ASP.NET, developers can make use of either C# or VB.NET language to create strong and scalable web applications that utilize the whole power of the .NET framework. 
• With ASP.NET, the many tools and libraries that include Web Forms, MVC, and Web API can be included with the type of development needed. 
• The framework also supports features like authentication, authorization, and session management, which makes developing secure web applications much easier. 

23. How does garbage collection in .NET work?

Ans:

• Garbage collection in .NET is an automatic memory management feature that reclaims memory used by objects no longer in use. 
• During runtime, when the garbage collector or GC runs, the unreferenced objects are removed from memory, thus lowering the risk of memory leak. 
• GC is generational it categorizes objects into generations based on the lifetime that would increase performance in terms of working on short-lived objects. 
• In addition to this, the garbage collector can be manually controlled and even used for releasing unmanaged resources by implementing the IDisposable interface for that purpose.

24. What is an assembly in .NET?

Ans:

• Assemblies are the smallest units of building .NET, compiled code libraries for applications. 
• An assembly is one kind of DLL or an EXE file containing compiled code in the form of Intermediate Language (IL). 
• It also contains an assembly manifest providing metadata about its identity, version, culture, and dependencies to other assemblies. 
• Versioning is the primary use associated with an assembly so that the same piece of code can be utilized in many applications without any duplication. 

25. What is namespace in .NET?

Ans:

Namespace in .NET is the manner of organizing and grouping related classes, interfaces, and other types to avoid naming conflicts and promote code readability. A container for classes that helps developers with scope and types within an application, namespaces may be nested to allow for a hierarchical organization of code and improve its maintainability. NSpaces are generally helpful in having structured code, as they allow better organization and avoid potential conflicts.

26. How to handle exceptions in NET?

Ans:

In NET, exception handling is accomplished with try-catch-finally blocks, which enable developers to handle runtime errors gracefully. Code that possibly raises an exception is placed inside a try block, and catch blocks are used to state how to handle particular types of exceptions. If an exception has been raised, control will be transferred to the appropriate catch block, where developers may log the error, provide feedback, or try to recover. If a final block exists, it executes code that must run whether an exception was thrown such as closing resources.

27. What are delegates?

Ans:

Delegates in .NET are a type-safe function pointer, enabling methods to be passed as parameters or assigned to variables. This feature allows developers to define callback methods while still making application components more flexible and decoupling in nature. A delegate is declared with a particular signature; this is identical to the methods it can invoke, thus ensuring type safety at compile time. It also forms the basis of events in .NET, thus providing support for event-driven programming.

28. What is an event in .NET?

Ans:

• Event in .NET is a mechanism, that enables an object to communicate with other objects about specific action occurrences. 
• Events based on delegates allow methods to be attached or subscribed to the event, which allows them to be invoked when the event is raised. 
• In this respect, the event source is decoupled from the event handlers this increases loose coupling and implies flexibility. 
• Events are perhaps the most widely used type of UI programming in which an action taken by a user, is replied to appropriately by an application. 

29. How does .NET support asynchronous programming?

Ans:

• .NET supports asynchronous programming, mainly through the async and await keywords, which simplifies the development of non-blocking code very much. 
• This model is really helpful for all I/O-bound operations example, file access or web requests, in which the application would otherwise block waiting for a response. 
• The Task-based Asynchronous Pattern, short for TAP, is widely used in .NET, which allows developers to work with tasks representing ongoing operations. 
• Asynchronous programming has enhanced the scalability of web applications by allowing numerous requests to be handled since threads are not tied up.

30. What is the Common Type System? 

Ans:

The Common Type System describes how types are declared, used, and managed. NET. It allows for a set of rules that govern data types so that all languages in .NET can share and work with types in predictable ways. The CTS categorizes types into value types, such as structs, and reference types, such as classes, ensuring type safety over all languages. Imposing a common type system makes possible the interoperability of languages between C#, VB.NET, and F#.

31. What are the types of assemblies that are present in .NET?

Ans:

Assemblies in .NET can be divided into two basic types. They are private and shared assemblies. Private assemblies refer to an assembly used by a specific application. It lies in the application directory. Shared assemblies, however, are supposed to be shared among various applications and placed in the Global Assembly Cache (GAC). Based on type, each assembly type can further be categorized into various kinds: static assemblies and dynamic assemblies .

32. What is the Windows Communication Foundation (WCF)?

Ans:

Windows Communication Foundation, WCF is a framework for building service-oriented applications in .NET. WCF will enable developers to write services that could converse across different platforms and protocols for the reason of ensuring the interoperation of various systems. It utilizes various options for communication, including HTTP, TCP, and MSMQ, so that applications can be integrated at one’s discretion. Using WCF, developers can design SOAP-based as well as RESTful services to cater to the differentiated needs of different clients.

33. What is Entity Framework?

Ans:

• It reduces the effort involved in interacting with data and databases so that developers can work directly within a .NET object containing information. 
• SQL coding is not as heavily relied upon since it supports a higher abstraction over traditional data-access methods than other frameworks do. 
• Developers can use LINQ queries to work with data. It supports a good number of database providers and enables code-first, database-first, and model-first approaches in database design.

34. What is LINQ in .NET?

Ans:

• LINQ is short for Language Integrated Query, and it is the feature in .NET that enables querying of data from various sources in a consistent language-integrated syntax. 
• It allows developers to write expressive and readable queries that support querying collections, databases, and XML. There are two styles of query; namely SQL-like query syntax and method syntax, which makes use of method chaining.
• Using LINQ, developers can perform complex data manipulations and transformations directly within their code. This not only raises productivity but can also make it unnecessary to write queries using specific query languages. 

35. What are the differences between Class versus Struct in .NET?

Ans:

• The main distinction of a class versus a struct in .NET relates to memory allocation and behavior. 
• Classes are reference types because they stay on the heap, and a variable holds a reference to that object. 
• Structs, on the other hand, are value types that stay on the stack and a variable holds the actual data. 
• When assign a class instance, are copying the reference, are copying the whole value.

36. What is the IDisposable interface?

Ans:

The interface in .NET is the IDisposable. This is an interface that allows releasing unmanaged resources that are not automatically cleaned up by the garbage collector, like file handles or database connections. A class implementing IDisposable can define its cleanup logic in the Dispose method. Developers can free resources explicitly when no longer needed on such applications that are resource-intensive; this can improve the performance of an application and prevent memory leaks by timely release of resources.

37. How to implement a web service in .NET?

Ans:

To implement a web service in .NET, first define a service contract by using a specific interface or class that is decorated with appropriate attributes. For instance, while using ASP.NET Web API, will have to create a controller class whose methods handle the HTTP requests, specifying routes as well as HTTP verbs applicable for the service endpoints. May also choose to apply WCF where first define the service contracts and then implement the service interface.

38. What is the .NET Standard?

Ans:

The .NET Standard is a set of APIs that provide a uniform platform to build cross-platform applications across different implementations of .NET, such as .NET Framework, .NET Core, and Xamarin. It provides a minimum level of functionality that has to be consistent across libraries in terms of compatibility and reusability in several .NET environments. This supports code sharing and simplifies the development for applications supporting multi-platforms.

39. What is the Model-View-Controller (MVC) pattern in ASP.NET?

Ans:

• The Model-View-Controller (MVC) pattern is one kind of architectural design pattern utilized in ASP.NET. The application is divided into three primary components: Model, View, and Controller. 
• This model represents the data and business logic of an application, which also manages data and state. The view serves the purpose of rendering a user interface and it handles user interactions. 
• The controller plays an intermediary role between the model and the view. Taking input, manipulating the model, and updating the view based on the new input conditions are some of the functions of this layer. 

40. What is the Common Type System? 

Ans:

• The Common Type System describes how types are declared, used, and managed. NET. Imposing a common type system makes possible the interoperability of languages between C#, VB.NET, and F#.
• It allows for a set of rules that govern data types so that all languages in .NET can share and work with types in predictable ways. 
• The CTS categorizes types into value types, such as structs, and reference types, such as classes, ensuring type safety over all languages.

41. What are the types of assemblies that are present in .NET?

Ans:

• Assemblies in .NET can be divided into two basic types. They are private and shared assemblies. 
• Private assemblies refer to an assembly used by a specific application. It lies in the application directory. 
• Shared assemblies, however, are supposed to be shared among various applications and placed in the Global Assembly Cache (GAC). 
• Knowing these types would help manage the dependencies and deployment of .NET applications.

42. What is the Windows Communication Foundation (WCF)?

Ans:

Windows Communication Foundation, WCF is a framework for building service-oriented applications in .NET. WCF will enable developers to write services that could converse across different platforms and protocols for the reason of ensuring the interoperation of various systems. It utilizes various options for communication, including HTTP, TCP, and MSMQ, so that applications can be integrated at one’s discretion.Using WCF, developers can design SOAP-based as well as RESTful services to cater to the differentiated needs of different clients.

43. What is Entity Framework?

Ans:

Entity Framework is an Object-Relational Mapping (ORM) framework designed for. NET. It reduces the effort involved in interacting with data and databases so that developers can work directly within a .NET object containing information. SQL coding is not as heavily relied upon since it supports a higher abstraction over traditional data-access methods than other frameworks do. Developers can use LINQ queries to work with data. 

44. What is LINQ in .NET?

Ans:

LINQ is short for Language Integrated Query, and it is the feature in .NET that enables querying of data from various sources in a consistent language-integrated syntax. In other words, it allows developers to write expressive and readable queries that support querying collections, databases, and XML. There are two styles of query; namely SQL-like query syntax and method syntax, which makes use of method chaining. This not only raises productivity but can also make it unnecessary to write queries using specific query languages.

45. What are the differences between Class versus Struct in .NET?

Ans:

• The main distinction of a class versus a struct in .NET relates to memory allocation and behavior.  Structs, on the other hand, are value types that stay on the stack and a variable holds the actual data. 
• These differences lead to different behaviors regarding copying, when assign a class instance, when assign a struct instance, are copying the whole value. 
• Classes can also be used to add further support for inheritance; thus, a struct can’t, as a programmer, inherit from another struct or class. 

46. What is the IDisposable interface?

Ans:

• The interface in .NET is the IDisposable. This is an interface that allows releasing unmanaged resources that are not automatically cleaned up by the garbage collector.
• Developers can free resources explicitly when no longer needed on such applications that are resource-intensive; this can improve the performance of an application and prevent memory leaks by timely release of resources.
• If it uses a statement with an object that implements IDisposable, even if an exception occurs, Dispose is called automatically.

47. How to implement a web service in .NET?

Ans:

• To implement a web service in .NET, first define a service contract by using a specific interface or class that is decorated with appropriate attributes. 
• May also choose to apply WCF where first define the service contracts and then implement the service interface. Then go ahead and deploy service in a web server or cloud environment.
• The steps for designing a web service using .NET are, by no means, very challenging and, again, still largely dependent upon the capabilities of the framework in web development.

48. What is the .NET Standard?

Ans:

The .NET Standard is a set of APIs that provide a uniform platform to build cross-platform applications across different implementations of .NET, such as .NET Framework, .NET Core, and Xamarin. It provides a minimum level of functionality that has to be consistent across libraries in terms of compatibility and reusability in several .NET environments. The ability to target .NET Standard permits library developers to code libraries that will work well across different platforms, easy to manage since they no longer have to control multiple code bases. 

49. What is the Model-View-Controller (MVC) pattern in ASP.NET?

Ans:

The Model-View-Controller (MVC) pattern is one kind of architectural design pattern utilized in ASP.NET. The application is divided into three primary components: Model, View, and Controller. This model represents the data and business logic of an application, which also manages data and state. The view serves the purpose of rendering a user interface it is a display of data that could be forwarded to the user, and it handles user interactions. The controller plays an intermediary role between the model and the view.

50. How does managed code run in the .NET framework?

Ans:

The three-step process of running in the context of the .NET framework starts with compilation to execute the managed code. At the time of building a .NET application, it gets compiled into MSIL which is independent of the platform. It is CLR that takes control during runtime and converts MSIL to native machine code and completes the job by JIT compilation. The CLR touches upon a multitude of services about memory allocation, garbage collection, security, and more, ensuring a safe execution environment. 

51. What is SignalR in .NET?

Ans:

• SignalR is a library for ASP.NET that simplifies real-time web functionality to applications.
• SignalR abstracts away the complexity of multiple transport protocols – WebSockets, Server-Sent Events, etc. along with automatic selection of the best available option. 
• This helps developers integrate SignalR easily into their existing ASP.NET applications. In a nutshell, SignalR brings interactivity and responsiveness to web applications.

52. What are some of the types of web applications can build with .NET?

Ans:

• Can build several types of web applications using. NET. Building ASP.NET MVC applications allows to have rich interactive user experiences. 
• ASP.Net Web Forms comes with an event-driven model to develop dynamic web pages. ASP.NET Core supports both cross-platform web APIs and server-side-rendered applications. 
• With these, can also build single-page applications (SPAs) with Angular or React, taking advantage of ASP.NET for SPAs.  With the help of Blazor, can now create interactive web UIs using C# instead of JavaScript.

53. What is middleware in ASP.NET Core?

Ans:

• Middleware in ASP.NET Core is the software assembled into an application pipeline to handle requests and responses. 
• Each component can process incoming requests, perform actions, and pass control to the next middleware of the pipeline. 
• It can handle cross-cutting concerns such as logging, authentication, and error handling. 
• The order of middleware in the pipeline is very significant because this decides how the requests will be processed.

54. How to implement security in an ASP.NET application?

Ans:

Implementation of security in an ASP.NET application incorporates layers like authentication, authorization, and protection of data. ASP.NET Identity is the framework encapsulating the user authentication and management of roles.Can make use of cookie authentication or JWT tokens, which come as a feature, to have user sessions securely. Authorization policy makes an impact on the system for controlling access to resources depending upon the roles or claims of a user.

55. What is the term virtual method in .NET?

Ans:

A virtual method in .NET is defined within a base class and can be overridden in the derived classes. In other words, it allows for polymorphism that makes it possible for a derived class to provide its specific implementation of a method. By declaring a method virtual, the derived class is allowed to change its behavior using the override keyword. If a subclass does not override a virtual method then by default, the subclass inherits the base class’s implementation for that method. The use of virtual methods provides runtime method binding, which enables flexible code.

56. What does boxing and unboxing refer to in .NET?

Ans:

Boxing in .NET is the operation of changing a value type (like int, char) into an object type or to a nullable type; this requires encapsulating the value in an object. In this way, value types can be used like reference types so they can be held within collections that require objects. The reverse operation is called unboxing. Unboxing converts the object back to its original type before boxing. Although boxing is flexible, it has a performance overhead due to memory allocation for the object. 

57. What is a thread pool?

Ans:

A set of reusable threads managed by CLR to handle multiple tasks efficiently. The thread pool maintains pools of pre-allocated, idle threads, ready to use, so the application doesn’t need to pay the price of reallocation for each task-it’s created and destroyed. This means that while a task is submitted, it is run by a thread from the pool, which will help improve the application’s performance as well as resource utilization. It adjusts, based on demand, how many active threads are present at any time.

58. How to unit test in .NET?

Ans:

• To unit test in .NET, may use a testing framework such as MSTest, NUnit, or xUnit.
• Unit tests are developed methods where developers test small units of code against expected behavior. 
• Test projects are created together with the main application that the test project references, so can test classes. 
• The framework provides attributes to define test cases and methods to make assertions on the expected outcome. 
• Tools such as Visual Studio offer integrated testing support, including the ability to run tests and view results. 

59. What are generics in .NET?

Ans:

• Generics in .NET allow programmers to write classes, interfaces, and methods with a placeholder for the data type, enhancing the reusability of code as well as its type safety. 
• Using generics will be able to create collections and data structures that work with any kind of data without losing performance. 
• Generics help to avoid boxing and unboxing when using value types, which reduces efficiency. Compiling time checking for generic types also reduces runtime errors. 
• Common examples include List<T>, Dictionary<TKey, TValue>, and other collection classes.

60. What is the purpose of the Global Sax file?

Ans:

The Global. Sax is an ASP.NET file that holds application-level event handlers and logic. It provides a point where developers may listen for events in their application’s lifecycle. The code can go into this file, initializing some settings of the application, configuring services, or even application-wide error handling. Global. Sax allows for centralized management of application behavior, as well as allowing the registration of routes and services within an application as it starts to play a crucial role in managing the lifecycle and behavior of an application.

61. How is caching implemented in ASP.NET?

Ans:

There are various methods of caching applications in ASP.NET. In-cache can either be in-memory, distributed, or output cache. In terms of MemoryCache, let a certain amount of data remain in memory to speed things up. Can set an expiration policy; the items get automatically removed from the cache. This is output-caching where it saves the rendered HTML output of the page; hence it reduces processing time because would be rendering the page once and then have a copy to use next time.

62. What is a configuration file in .NET?

Ans:

A configuration file in .NET typically is web. Config for web applications and app. config for desktop applications. These contain application settings, connection strings, and other configurable parameters. In the XML format, configuration files are written, and one does not have to recompile the application when changing settings; instead, configuration file values can be retrieved and used at runtime with the help of the ConfigurationManager class.

63. How to connect to a database in .NET?

Ans:

• Use ADO.NET when connecting to any database in .NET; it contains classes like SqlConnection, SqlCommand, and SqlDataReader. 
• Begin by creating a connection string that says where database is located and everything concerning credentials.  Create a SqlConnection object based on that string by opening the connection. 
• With a SqlCommand can execute SQL queries or stored procedures.Data can be read using SqlDataReader or filled into a DataSet.
• Don’t forget to handle connections correctly using the statements to ensure automatic disposal.

64. What is ADO.NET?

Ans:

• ADO.NET is a part of the .NET Framework classes that permits developers to access and manipulate data coming from a wide range of sources like SQL Server, Oracle, and XML. 
• It offers two critical components the DataSet, a representing cache for in-memory data, and the DataReader, offering high-performance, read-only access to data from a data source. 
• ADO.NET supports disconnected architecture; therefore, an application can work with the data while keeping resource utilization minimum. It also includes transaction support and can interact with data that falls within the XML format.

65. What are the differences between IEnumerable and IQueryable?

Ans:

• IEnumerable is used for collections that can be enumerated forward only. It is an in-memory object and therefore quite useful for the collection that lives only in memory. 
• It is the opposite of IQueryable and is typically used for querying data from a data source LINQ typically uses a database. It supports deferred execution; that is, the query is only executed when it is needed. 
• This class will optimize the query by translating it into SQL, whereas IEnumerable will execute a query in memory. Use the IQueryable class for database queries and IEnumerable for in-memory collections.

66. What is a background worker in .NET?

Ans:

The BackgroundWorker class in .NET provides a means to run operations on a separate, dedicated thread. This is particularly useful for time-consuming tasks that should not block the main UI thread, which improves application responsiveness. It also has some support for cancellation and progress reporting, so the UI can update as the operation progresses. It is often used in Windows Forms applications for tasks like file processing or network operations.

67. What is Cross-Origin Resource Sharing (.NET)?

Ans:

CORS is an online security feature implemented within a web browser it will determine whether to provide the resource or deny the request for access based on a different origin from where the web page was served. In .NET, can configure the CORS to allow certain domains to access resources. Here’s how can implement CORS in ASP.NET application using the Microsoft.AspNetCore.Cors package, configured in Startup. Cs file. This calls for the definition of policies that detail allowed origins, methods, and headers.

68. How would implement authentication within an ASP.NET application?

Ans:

Authentication within an ASP.NET application can be implemented using built-in capabilities such as Forms Authentication, Windows Authentication, or ASP.NET Identity. For Forms Authentication, create a login page that validates user credentials and will issue a cookie to control the session. ASP.NET Identity provides a more comprehensive solution to user management, which includes roles and claims. Most of this configuration will occur in the Startup.cs file when working with authentication schemes and policies.

69. What are web forms in ASP.NET?

Ans:

• Web Forms is a framework in ASP.NET for dynamic web applications. It is a page-based model: developers could create web pages by using both HTML as well as server-side controls. 
• Each control encapsulates rendering as well as state management, which makes the development easier. Web Forms supports event-driven programming, meaning developers can respond to client events.
• While it does offer rapid development, many of today’s modern applications prefer using ASP.NET MVC or ASP.NET Core for the added control and flexibility.

70. What does the HttpContext class?

Ans:

The class HttpContext in ASP.NET captures every HTTP-related information concerning one HTTP request. It gives access to request and response data such as headers, query strings, and form data. Developers make use of HttpContext to manage session state, cookies, and application state. It serves as the connecting link between the web server and an ASP.NET application, making it possible to read and alter the data for the request/response that occurs as part of the lifecycle of a request. 

71. How to maintain state in ASP.NET?

Ans:

State management in ASP.NET is the process of holding information between multiple requests. ASP.NET provides several options for state management. View State maintains data on the client side between postbacks. Session State preserves user information on the server for the entire session, and Application State is applied to any data shared by all users. Another thing could do is use cookies to store small pieces of information unique to the user. Again, that depends on the nature of application being scalable, secure, and performant.

72. What are the types of sessions in .NET?

Ans:

• Sessions can be managed in .NET in the following ways: In-Process Session is storing session information in memory on the web server, where it has access speed but not scalability.
• Data will be stored in a different process, which permits out-of-process storage and supports scalability. SQL Server Session Session data will exist in a database, which supports durability and allows web farms. 
• Custom Session Providers can be created depending on the special storage needs. All the options have trade-offs related to performance, scalability, and complexity.

73. What is the difference between ViewBag and ViewData?

Ans:

• ViewBag and ViewData are two different methods that can be used to pass information from a controller to a view in ASP.NET MVC. 
• The only difference is that ViewData is a dictionary object that stores key-value pairs and have to typecast while extracting values. 
• ViewBag is a dynamic property. It means that the developer has to typecast nothing to access data, which makes it more developer-friendly. 
• It all depends on a dynamic type of keyword, which will lead to runtime errors if keywords are misspelled.

74. How to implement logging in a .NET application?

Ans:

Can implement logging in a .NET application using a few different frameworks, the most popular of which are Serilog, NLog, and log4net. Begin by installing a logging framework via NuGet and then doing some configuration within an application’s startup. It is possible to configure the targets for where the logs are output to include files, databases, or cloud services. Then inject the logger into classes using dependency injection. Proper logging involves logging levels, such as Info, Warn, and Error, which group messages.

75. What is the Service Locator pattern?

Ans:

The Service Locator pattern is one of the design patterns that retrieve an application’s dependency. It can be considered as a central registry issuing access to multiple services without the classes containing information about their implementation. It promotes loose coupling and makes testing easier since object creation is detached from classes that use the services. At the same time, it introduces hidden dependencies and obfuscates code.

76. What is LINQ query syntax?

Ans:

• LINQ query syntax is a way to access data from collections or databases directly within C# using a SQL-like syntax. Write queries against arrays, lists, or databases using keywords such as from, where select, and orderly. 
• Because this syntax reads more like SQL, it’s much easier to read than normal Linq with the same static type checking and IntelliSense available. 
• This is made easy and expressive because LINQ query syntax supports filtering, grouping, and sorting operations.

77. What is a data context in Entity Framework?

Ans:

• A data context in Entity Framework will act as a bridge between the application and the database that manages the connection and assists in CRUD operations. 
• The context based on changes to entities makes it possible to retrieve data efficiently and update it in real time. 
• When creating a service application using Entity Framework Code First, the data context defines how entity classes are mapped to database tables. 
• Developers would often encapsulate database logic and configurations within a class that inherits DbContext.

78. How can establish a RESTful service in .NET?

Ans:

• Building a web API of a RESTful service can be done on top of the ASP.NET core, starting with defining a controller class that extends ControllerBase. 
• Then use attributes like [HttpGet], [HttpPost], [HttpPut], and [HttpDelete] to define the endpoints and their corresponding HTTP methods. 
• The routing configuration inside Startup.cs tells ASP.NET how requests should map to controllers.  Ensure API endpoints are protected with the appropriate authentication and authorization.

79. What does a controller do in MVC?

Ans:

A Controller in the MVC (Model-View-Controller) pattern acts as a middleman between the Model and the View. The controller accepts user input, processes requests, and changes data through interaction with the Model. After processing, the controller will determine which View to return as the response. Controllers are also responsible for controlling the flow of the application. They include validation of the input and implementing the business logic.

80. What is middleware in ASP.NET Core?

Ans:

Middleware in ASP.NET Core is a piece of software that executes each request to an application. What it does is handle requests and responses, and thus it can be used in adding custom processing logic, such as authentication and loggùng as well as error handling. Middleware can be configured between lines in the Startup.cs file in the Configure method where can define the order of execution of components. Each middleware can either short-circuit the request pipeline or pass control to the next middleware.

81. How to handle file uploads in ASP.NET?

Ans:

In an ASP.NET Core application, would typically use the IFormFile interface to handle file uploads in ASP.NET. First, would create a form in HTML containing an <input type=”file”> element for this purpose. In the controller, might have an action where it accepts the uploaded file as a parameter. To save the file to an appointed directory, methods like FileStream or CopyToAsync would be used. Validate file types and sizes for security reasons. Consider also some use of middleware for handling greater uploads.

82. What does HttpClient do?

Ans:

• HttpClient is a class in the .NET Framework that facilitates the sending of an HTTP request and reception of an HTTP response from a resource identified by a URI. 
• HttpClient is ideal for calling RESTful services or APIs because it takes care of anything requiring headers in request, query parameters, and content. 
• This supports modern features like cancellation tokens and automatic handling of cookies. To avoid socket exhaustion, instantiate HttpClient once and reuse it throughout the application.

83. What are the advantages of Azure? NET.

Ans:

• There are lots of advantages to using Azure with .NET including scalability, security, and integrations of other Microsoft services. 
• Having Azure App Services, Azure Functions, and Azure SQL Database, among many more cloud services, it can be easily deployed by developers. 
• The system has also supported seamless DevOps practices using tools such as Azure DevOps, and GitHub Actions. 
• With the global infrastructure of Azure, applications may be deployed closer to users thereby improving performance. 

84. What is ASP.NET? How do implement role-based security in ASP.NET?

Ans:

• Role-based security on an ASP.NET application is usually implemented by using ASP.NET Identity. 
• The RoleManager would be used for the creation and management of those roles, while the UserManager can be used to assign users to roles. 
• The following attribute would be used within controllers or action methods to restrict access based on the user’s role.
• Also, include the role management in the Startup.cs file. This way, specific resources could not be accessed without proper authorization.

85. What is dependency inversion in .NET?

Ans:

Dependency inversion refers to the software design principle that says that high-level modules should depend on abstractions rather than concrete implementations. In the context of .NET, this can very often be fulfilled through interfaces or abstract classes, which are much more flexible and easier to test. Can replace the implementations without modifying the high-level code by inverting dependencies.

86. How to raise custom exceptions in .NET?

Ans:

To raise custom exceptions in .NET, might inherit a new exception class from the base Exception class. Can extend it further with more properties or methods to add further details about the error. Can surround application code with a try-catch block to catch the custom exception and allow for some form of graceful error handling. The user can use a logging framework to log the details of the exception.

87. How does it relate to a partial class in .NET?

Ans:

A partial class in .NET is a way of breaking the definition of a class into pieces spread across multiple files. It is also useful to organize large classes or to separate auto-generated code, such as designer files from code developed by the developer. All parts must include the keyword and be contained in the same namespace. The compiler will combine all parts into a single class during the compilation of the application.

88. How will handle application configuration settings in .NET?

Ans:

• Application configuration in .NET can be controlled by appsettings.json files in ASP.NET Core or the use of the web. 
• Config in traditional ASP.NET applications; both these store key connection strings or application-specific settings in the form of a list of key-value pairs. 
• Can use the IConfiguration interface to access application settings in ASP.NET Core.  It supports multiple sources, including JSON files, environment variables, and command-line arguments.

89. What is the role of the Task Parallel Library of .NET?

Ans:

• The Task Parallel Library, abbreviated TPL, is a .NET class library that provides public types and APIs for parallel programming. 
• Utilizing the TPL gives a strong framework for the asynchronous and parallel management of tasks to write more efficient and scalable applications. 
• TPL provides the Task class for representing an asynchronous operation and is complemented with methods, used for creating, scheduling, and managing tasks. 
• It supports parallel loops and LINQ queries for data processing. Developers can also use TPL to improve the responsiveness of an application, as well as optimize available system resources.

90. How to implement OAuth authentication in an ASP.NET application?

Ans:

Implement OAuth authentication have the choice of configuring an ASP.NET application with external authentication providers such as Google, Facebook, or Microsoft. In ASP .NET Core.OAuth package. First, need to register authentication services in Startup. Cs. Inside it, specify the client ID and secret of the provider. Implement callback methods as necessary to address authentication and get user information.

1. What is the .NET Framework?

Ans:

The .NET Framework is an integrated framework developed by Microsoft that is free of cost and provides an all-inclusive environment for application development, deployment, and execution mostly on Windows. A significant library of the .NET Framework known as the Framework Class Library of .NET Framework is very large which possesses re-usable code for commonly repeated tasks while programming.

2. What are some of the popular components of .NET?

Ans:

Some common components of the .NET Framework include the Common Language Runtime (CLR), which provides an execution environment for .NET applications, handling memory management, security, and exception handling. The Framework Class Library offers a very comprehensive library of pre-written classes and functions for developers to implement.

3. What does the JIT mean in .NET?

Ans:

• JIT stands for Just-In-Time compilation, an important process in the .NET Framework that translates MSIL code into the native machine code. 
• The positive effect of JIT compilation is the ability of the interpreter to compile only necessary code when required at runtime rather than compiling the whole application before running.
• The translation is only performed at runtime making it possible to run the code on a host computer.  There are three JIT compilers Pre-JIT, Normal JIT, and Eco JIT, and they are all intended for certain purposes.

4. What is the abbreviation MSIL?

Ans:

• MSIL is an abbreviation for, which is a low-level programming language used within the .NET Framework. It improves the abstraction between the high-level programming language and the native code.
• The intermediate, platform-independent language MSIL allows a .NET application to run on any system with a compatible CLR.
• Enhances its portability over different architectures, for instance supporting Just-In-Time compilation or runtime code optimization.

5. What is CTS?

Ans:

CTS is the short form for Common Type System. It is the core element of the .NET Framework that describes how types are declared, used, and managed in the runtime environment. It does create a set of rules and guidelines for data types, so they’re all consistent across different languages on .NET, which improves interoperability. With the use of CTS, the developers may implement applications in multiple languages while type safety and compatibility are still provided.

6. What are the key differences between COBOL and modern programming languages?

Ans:

Feature	COBOL	Modern Programming Languages
Syntax	Verbose and rigid, emphasizing readability	More concise and flexible syntax that enhances developer productivity.
Data Types	Limited to basic types (e.g., numeric, alphanumeric)	A rich variety of data types, including complex structures like collections and objects
Object-Oriented Support	Primarily procedural, with limited support for object-oriented programming	Strong support for object-oriented principles, enabling better design and code reuse
Use Cases	Mainly used in business and financial applications	Applicable across various domains, including web, mobile, and data science applications.
Performance	Optimized for batch processing and handling large data sets	Performance varies, with many languages focusing on speed and efficiency depending on the use case
Community and Support	Smaller, primarily focused on legacy systems	Large, active communities that support rapid evolution and modern development practices

7. What is. NET’s notion of ‘state management’?

Ans:

In the .NET context, state management refers to the methods adopted to preserve the state of an application across multiple requests. In a web application, where HTTP is stateless, the necessity to keep user data and preferences quite important for a seamless user experience. .NET supports several techniques for state management, including ViewState which keeps data on the page itself, and Session state, which maintains data across multiple requests for a specific user. 

8. What is CLR in .NET?

Ans:

CLR stands for Common Language Runtime. It is the central run-time component in the .NET Framework that manages the execution of .NET applications. Services provided by the CLR include memory management, garbage collection, and exception handling to keep the applications running smoothly and efficiently. CLR enforces strict security policies and grants permission to access code to protect sensitive data and resources. It also enables cross-language interoperability because code written in different .NET languages runs together seamlessly.

9. What’s the difference between managed code and unmanaged code in .NET?

Ans:

• Managed code is executed by the CLR; hence, it enjoys automatic memory management, security, and exception handling. 
• Unmanaged code is executed directly by the operating system and does not experience the management features of the CLR. 
• It employs languages, including C or C++ with unmanaged memory or does not exploit features of the managed code. 
• Managed code will provide a more secure and controlled environment than languages that employ unmanaged code.

10. What is CLS?

Ans:

• CLS is an abbreviation for Common Language Specification. CLS is a subset of CTS representing a set of rules of language interoperability within the .NET Framework. 
• The CLS will determine which features of languages in .NET are guaranteed to be available to all other languages as well, thereby implying uniform behavior and compatibility. 
• Being consistent with CLS standards allows library developers to produce libraries as well as components that could be exploited in many of the programming languages used in the .NET environment. 

11. What is the difference between System.StringBuilder and System.String?

Ans:

• System. The string is an immutable sequence of characters, which once the string is created can’t be modified later. System.
• Any modification on a string must be made by creating a new string object, which then involves overhead in performance when many modifications occur.  
• Another difference is that System.StringBuilder is mutable. It is used where the string content must be changed frequently. 

12. What does LINQ stand for?

Ans:

LINQ stands for Language Integrated Query, and it is a component of. NET. This enables developers to query different sources of data using an all-encompassing syntax directly in their programming language. It results in easier work with collections of data, such as arrays or lists, XML, and databases. Developers can write quite expressive and readable queries using C# or VB.NET and include querying capabilities directly inside the language. This reduces the need for complex SQL statements and allows compile-time checking of queries. 

13. What is an assembly in the .NET platform?

Ans:

An assembly is a basic deployment unit of the .NET Framework, which combines code, resources, and metadata in a single file representing compilation. Assemblies can be in the form of either DLL or EXE files, representing a logical group of types and resources. Assemblies enable capabilities such as versioning, security, and deployment to make CLR-managed code possible. They also carry an assembly manifest which carries information regarding the identity, version, and dependencies of assemblies.

14. What are the components of an assembly in .NET?

Ans:

An assembly in .NET is comprised of several elements, such as the assembly manifest, which includes meta-information on the assembly’s identity, version, and culture. The manifest also includes all the types and resources in the assembly, as well as any dependencies on other assemblies. Another element is the Intermediate Language (IL) code or the compiled version of the source code that the CLR executes.

15. What is caching?

Ans:

• Caching is a process of keeping frequently accessed data in a temporary storage location called cache, and improvements in application performance along with reduced data retrieval times occur. 
• In .NET, caching can be implemented at several levels application, session, and output cachin; each is used for different purposes. 
• Application caching holds the data that can be reused multiple times from different sessions, whereas session caching holds the data that is specific to a user’s session. 
• Output caching keeps the output of pages or controls, once rendered, so that there is no need to recreate these contents on subsequent requests. It cuts down on repeated data access as well as computation

16. What is the purpose of memory-mapped files in the .NET platform?

Ans:

Using memory-mapped files in .NET is a technique for sharing data among processes efficiently or accessing files on disk as though they are in memory. The key aspect is that this technique will enable large files to be mapped into the address space of an application and accessed fast, without the necessity of loading the entire file into memory. As a result, they demonstrate better performance for I/O-bound operations.

17. What does manifest mean in the .NET framework?

Ans:

The manifest in the .NET framework is assumed to be a detailed metadata file, carrying all important information about the said assembly. This includes name, version, culture, and public key token which are very crucial for an assembly’s identity and version control. The manifest is a list of all the types defined in the assembly along with their visibility and it must have references to other assemblies to ensure that all the constituent parts are available when needed at run-time.

18. How many versions of the .NET framework exist? 

Ans:

The .NET framework has evolved, and starting with its invention, the important versions released are countless. The first version, .NET Framework 1.0, was developed and released in 2002, and the core of the framework was the first solid component. In addition, 2.0, 3.0, and 3.5 introduced WPF, WCF, and LINQ. The .NET Framework 4.0 improved security and performance: it introduced the task parallel library (TPL) for asynchronous programming. The last major update is the .NET Framework 4.8, which was released in 2019 and comprises the following updates. 

19. What is the GAC?

Ans:

• The Global Assembly Cache (GAC) is a central repository in the .NET Framework that holds shared assemblies so that many applications can use the same assembly without duplication. 
• The GAC also helps make updates easier since an application can reference a new version of an assembly without having to change its code. 
• This centralization makes the shared common components easier to deploy and manage across an enterprise application. 

20. How Does .NET Support the Use of Multiple Languages? 

Ans:

The .NET framework supports multiple programming languages through the use of CLR and CTS. This means that different languages, such as C#, VB.NET, and F# are compiled into a common Intermediate Language so they can run on the same platform under the CLR. The CTS ensures that all languages share the same set of data types and behaviors to ensure that there is smooth interoperability. Developers could then always use the best language for their task, utilize libraries and components written in other languages.

21. What’s the difference between .NET Core and .NET Framework?

Ans:

.NET Core is an open-source version of the .NET framework, cross-platform. The .NET Framework has been designed by Microsoft for contemporary applications running on Windows, macOS, and Linux. In contrast, the .NET Framework is Windows-only and mainly for desktop as well as web application development, depending on the features of the Windows system. Taking performance and scalability into consideration, .NET Core appears better suited to cloud applications, as well as to microservices.

22. What is ASP.NET?

Ans:

• ASP.NET is a web application framework that runs within the .NET ecosystem for the development of dynamic web applications, services, and APIs. 
• In ASP.NET, developers can make use of either C# or VB.NET language to create strong and scalable web applications that utilize the whole power of the .NET framework. 
• With ASP.NET, the many tools and libraries that include Web Forms, MVC, and Web API can be included with the type of development needed. 
• The framework also supports features like authentication, authorization, and session management, which makes developing secure web applications much easier. 

23. How does garbage collection in .NET work?

Ans:

• Garbage collection in .NET is an automatic memory management feature that reclaims memory used by objects no longer in use. 
• During runtime, when the garbage collector or GC runs, the unreferenced objects are removed from memory, thus lowering the risk of memory leak. 
• GC is generational it categorizes objects into generations based on the lifetime that would increase performance in terms of working on short-lived objects. 
• In addition to this, the garbage collector can be manually controlled and even used for releasing unmanaged resources by implementing the IDisposable interface for that purpose.

24. What is an assembly in .NET?

Ans:

• Assemblies are the smallest units of building .NET, compiled code libraries for applications. 
• An assembly is one kind of DLL or an EXE file containing compiled code in the form of Intermediate Language (IL). 
• It also contains an assembly manifest providing metadata about its identity, version, culture, and dependencies to other assemblies. 
• Versioning is the primary use associated with an assembly so that the same piece of code can be utilized in many applications without any duplication. 

25. What is namespace in .NET?

Ans:

Namespace in .NET is the manner of organizing and grouping related classes, interfaces, and other types to avoid naming conflicts and promote code readability. A container for classes that helps developers with scope and types within an application, namespaces may be nested to allow for a hierarchical organization of code and improve its maintainability. NSpaces are generally helpful in having structured code, as they allow better organization and avoid potential conflicts.

26. How to handle exceptions in NET?

Ans:

In NET, exception handling is accomplished with try-catch-finally blocks, which enable developers to handle runtime errors gracefully. Code that possibly raises an exception is placed inside a try block, and catch blocks are used to state how to handle particular types of exceptions. If an exception has been raised, control will be transferred to the appropriate catch block, where developers may log the error, provide feedback, or try to recover. If a final block exists, it executes code that must run whether an exception was thrown such as closing resources.

27. What are delegates?

Ans:

Delegates in .NET are a type-safe function pointer, enabling methods to be passed as parameters or assigned to variables. This feature allows developers to define callback methods while still making application components more flexible and decoupling in nature. A delegate is declared with a particular signature; this is identical to the methods it can invoke, thus ensuring type safety at compile time. It also forms the basis of events in .NET, thus providing support for event-driven programming.

28. What is an event in .NET?

Ans:

• Event in .NET is a mechanism, that enables an object to communicate with other objects about specific action occurrences. 
• Events based on delegates allow methods to be attached or subscribed to the event, which allows them to be invoked when the event is raised. 
• In this respect, the event source is decoupled from the event handlers this increases loose coupling and implies flexibility. 
• Events are perhaps the most widely used type of UI programming in which an action taken by a user, is replied to appropriately by an application. 

29. How does .NET support asynchronous programming?

Ans:

• .NET supports asynchronous programming, mainly through the async and await keywords, which simplifies the development of non-blocking code very much. 
• This model is really helpful for all I/O-bound operations example, file access or web requests, in which the application would otherwise block waiting for a response. 
• The Task-based Asynchronous Pattern, short for TAP, is widely used in .NET, which allows developers to work with tasks representing ongoing operations. 
• Asynchronous programming has enhanced the scalability of web applications by allowing numerous requests to be handled since threads are not tied up.

30. What is the Common Type System? 

Ans:

The Common Type System describes how types are declared, used, and managed. NET. It allows for a set of rules that govern data types so that all languages in .NET can share and work with types in predictable ways. The CTS categorizes types into value types, such as structs, and reference types, such as classes, ensuring type safety over all languages. Imposing a common type system makes possible the interoperability of languages between C#, VB.NET, and F#.

31. What are the types of assemblies that are present in .NET?

Ans:

Assemblies in .NET can be divided into two basic types. They are private and shared assemblies. Private assemblies refer to an assembly used by a specific application. It lies in the application directory. Shared assemblies, however, are supposed to be shared among various applications and placed in the Global Assembly Cache (GAC). Based on type, each assembly type can further be categorized into various kinds: static assemblies and dynamic assemblies .

32. What is the Windows Communication Foundation (WCF)?

Ans:

Windows Communication Foundation, WCF is a framework for building service-oriented applications in .NET. WCF will enable developers to write services that could converse across different platforms and protocols for the reason of ensuring the interoperation of various systems. It utilizes various options for communication, including HTTP, TCP, and MSMQ, so that applications can be integrated at one’s discretion. Using WCF, developers can design SOAP-based as well as RESTful services to cater to the differentiated needs of different clients.

33. What is Entity Framework?

Ans:

• It reduces the effort involved in interacting with data and databases so that developers can work directly within a .NET object containing information. 
• SQL coding is not as heavily relied upon since it supports a higher abstraction over traditional data-access methods than other frameworks do. 
• Developers can use LINQ queries to work with data. It supports a good number of database providers and enables code-first, database-first, and model-first approaches in database design.

34. What is LINQ in .NET?

Ans:

• LINQ is short for Language Integrated Query, and it is the feature in .NET that enables querying of data from various sources in a consistent language-integrated syntax. 
• It allows developers to write expressive and readable queries that support querying collections, databases, and XML. There are two styles of query; namely SQL-like query syntax and method syntax, which makes use of method chaining.
• Using LINQ, developers can perform complex data manipulations and transformations directly within their code. This not only raises productivity but can also make it unnecessary to write queries using specific query languages. 

35. What are the differences between Class versus Struct in .NET?

Ans:

• The main distinction of a class versus a struct in .NET relates to memory allocation and behavior. 
• Classes are reference types because they stay on the heap, and a variable holds a reference to that object. 
• Structs, on the other hand, are value types that stay on the stack and a variable holds the actual data. 
• When assign a class instance, are copying the reference, are copying the whole value.

36. What is the IDisposable interface?

Ans:

The interface in .NET is the IDisposable. This is an interface that allows releasing unmanaged resources that are not automatically cleaned up by the garbage collector, like file handles or database connections. A class implementing IDisposable can define its cleanup logic in the Dispose method. Developers can free resources explicitly when no longer needed on such applications that are resource-intensive; this can improve the performance of an application and prevent memory leaks by timely release of resources.

37. How to implement a web service in .NET?

Ans:

To implement a web service in .NET, first define a service contract by using a specific interface or class that is decorated with appropriate attributes. For instance, while using ASP.NET Web API, will have to create a controller class whose methods handle the HTTP requests, specifying routes as well as HTTP verbs applicable for the service endpoints. May also choose to apply WCF where first define the service contracts and then implement the service interface.

38. What is the .NET Standard?

Ans:

The .NET Standard is a set of APIs that provide a uniform platform to build cross-platform applications across different implementations of .NET, such as .NET Framework, .NET Core, and Xamarin. It provides a minimum level of functionality that has to be consistent across libraries in terms of compatibility and reusability in several .NET environments. This supports code sharing and simplifies the development for applications supporting multi-platforms.

39. What is the Model-View-Controller (MVC) pattern in ASP.NET?

Ans:

• The Model-View-Controller (MVC) pattern is one kind of architectural design pattern utilized in ASP.NET. The application is divided into three primary components: Model, View, and Controller. 
• This model represents the data and business logic of an application, which also manages data and state. The view serves the purpose of rendering a user interface and it handles user interactions. 
• The controller plays an intermediary role between the model and the view. Taking input, manipulating the model, and updating the view based on the new input conditions are some of the functions of this layer. 

40. What is the Common Type System? 

Ans:

• The Common Type System describes how types are declared, used, and managed. NET. Imposing a common type system makes possible the interoperability of languages between C#, VB.NET, and F#.
• It allows for a set of rules that govern data types so that all languages in .NET can share and work with types in predictable ways. 
• The CTS categorizes types into value types, such as structs, and reference types, such as classes, ensuring type safety over all languages.

41. What are the types of assemblies that are present in .NET?

Ans:

• Assemblies in .NET can be divided into two basic types. They are private and shared assemblies. 
• Private assemblies refer to an assembly used by a specific application. It lies in the application directory. 
• Shared assemblies, however, are supposed to be shared among various applications and placed in the Global Assembly Cache (GAC). 
• Knowing these types would help manage the dependencies and deployment of .NET applications.

42. What is the Windows Communication Foundation (WCF)?

Ans:

Windows Communication Foundation, WCF is a framework for building service-oriented applications in .NET. WCF will enable developers to write services that could converse across different platforms and protocols for the reason of ensuring the interoperation of various systems. It utilizes various options for communication, including HTTP, TCP, and MSMQ, so that applications can be integrated at one’s discretion.Using WCF, developers can design SOAP-based as well as RESTful services to cater to the differentiated needs of different clients.

43. What is Entity Framework?

Ans:

Entity Framework is an Object-Relational Mapping (ORM) framework designed for. NET. It reduces the effort involved in interacting with data and databases so that developers can work directly within a .NET object containing information. SQL coding is not as heavily relied upon since it supports a higher abstraction over traditional data-access methods than other frameworks do. Developers can use LINQ queries to work with data. 

44. What is LINQ in .NET?

Ans:

LINQ is short for Language Integrated Query, and it is the feature in .NET that enables querying of data from various sources in a consistent language-integrated syntax. In other words, it allows developers to write expressive and readable queries that support querying collections, databases, and XML. There are two styles of query; namely SQL-like query syntax and method syntax, which makes use of method chaining. This not only raises productivity but can also make it unnecessary to write queries using specific query languages.

45. What are the differences between Class versus Struct in .NET?

Ans:

• The main distinction of a class versus a struct in .NET relates to memory allocation and behavior.  Structs, on the other hand, are value types that stay on the stack and a variable holds the actual data. 
• These differences lead to different behaviors regarding copying, when assign a class instance, when assign a struct instance, are copying the whole value. 
• Classes can also be used to add further support for inheritance; thus, a struct can’t, as a programmer, inherit from another struct or class. 

46. What is the IDisposable interface?

Ans:

• The interface in .NET is the IDisposable. This is an interface that allows releasing unmanaged resources that are not automatically cleaned up by the garbage collector.
• Developers can free resources explicitly when no longer needed on such applications that are resource-intensive; this can improve the performance of an application and prevent memory leaks by timely release of resources.
• If it uses a statement with an object that implements IDisposable, even if an exception occurs, Dispose is called automatically.

47. How to implement a web service in .NET?

Ans:

• To implement a web service in .NET, first define a service contract by using a specific interface or class that is decorated with appropriate attributes. 
• May also choose to apply WCF where first define the service contracts and then implement the service interface. Then go ahead and deploy service in a web server or cloud environment.
• The steps for designing a web service using .NET are, by no means, very challenging and, again, still largely dependent upon the capabilities of the framework in web development.

48. What is the .NET Standard?

Ans:

The .NET Standard is a set of APIs that provide a uniform platform to build cross-platform applications across different implementations of .NET, such as .NET Framework, .NET Core, and Xamarin. It provides a minimum level of functionality that has to be consistent across libraries in terms of compatibility and reusability in several .NET environments. The ability to target .NET Standard permits library developers to code libraries that will work well across different platforms, easy to manage since they no longer have to control multiple code bases. 

49. What is the Model-View-Controller (MVC) pattern in ASP.NET?

Ans:

The Model-View-Controller (MVC) pattern is one kind of architectural design pattern utilized in ASP.NET. The application is divided into three primary components: Model, View, and Controller. This model represents the data and business logic of an application, which also manages data and state. The view serves the purpose of rendering a user interface it is a display of data that could be forwarded to the user, and it handles user interactions. The controller plays an intermediary role between the model and the view.

50. How does managed code run in the .NET framework?

Ans:

The three-step process of running in the context of the .NET framework starts with compilation to execute the managed code. At the time of building a .NET application, it gets compiled into MSIL which is independent of the platform. It is CLR that takes control during runtime and converts MSIL to native machine code and completes the job by JIT compilation. The CLR touches upon a multitude of services about memory allocation, garbage collection, security, and more, ensuring a safe execution environment. 

51. What is SignalR in .NET?

Ans:

• SignalR is a library for ASP.NET that simplifies real-time web functionality to applications.
• SignalR abstracts away the complexity of multiple transport protocols – WebSockets, Server-Sent Events, etc. along with automatic selection of the best available option. 
• This helps developers integrate SignalR easily into their existing ASP.NET applications. In a nutshell, SignalR brings interactivity and responsiveness to web applications.

52. What are some of the types of web applications can build with .NET?

Ans:

• Can build several types of web applications using. NET. Building ASP.NET MVC applications allows to have rich interactive user experiences. 
• ASP.Net Web Forms comes with an event-driven model to develop dynamic web pages. ASP.NET Core supports both cross-platform web APIs and server-side-rendered applications. 
• With these, can also build single-page applications (SPAs) with Angular or React, taking advantage of ASP.NET for SPAs.  With the help of Blazor, can now create interactive web UIs using C# instead of JavaScript.

53. What is middleware in ASP.NET Core?

Ans:

• Middleware in ASP.NET Core is the software assembled into an application pipeline to handle requests and responses. 
• Each component can process incoming requests, perform actions, and pass control to the next middleware of the pipeline. 
• It can handle cross-cutting concerns such as logging, authentication, and error handling. 
• The order of middleware in the pipeline is very significant because this decides how the requests will be processed.

54. How to implement security in an ASP.NET application?

Ans:

Implementation of security in an ASP.NET application incorporates layers like authentication, authorization, and protection of data. ASP.NET Identity is the framework encapsulating the user authentication and management of roles.Can make use of cookie authentication or JWT tokens, which come as a feature, to have user sessions securely. Authorization policy makes an impact on the system for controlling access to resources depending upon the roles or claims of a user.

55. What is the term virtual method in .NET?

Ans:

A virtual method in .NET is defined within a base class and can be overridden in the derived classes. In other words, it allows for polymorphism that makes it possible for a derived class to provide its specific implementation of a method. By declaring a method virtual, the derived class is allowed to change its behavior using the override keyword. If a subclass does not override a virtual method then by default, the subclass inherits the base class’s implementation for that method. The use of virtual methods provides runtime method binding, which enables flexible code.

56. What does boxing and unboxing refer to in .NET?

Ans:

Boxing in .NET is the operation of changing a value type (like int, char) into an object type or to a nullable type; this requires encapsulating the value in an object. In this way, value types can be used like reference types so they can be held within collections that require objects. The reverse operation is called unboxing. Unboxing converts the object back to its original type before boxing. Although boxing is flexible, it has a performance overhead due to memory allocation for the object. 

57. What is a thread pool?

Ans:

A set of reusable threads managed by CLR to handle multiple tasks efficiently. The thread pool maintains pools of pre-allocated, idle threads, ready to use, so the application doesn’t need to pay the price of reallocation for each task-it’s created and destroyed. This means that while a task is submitted, it is run by a thread from the pool, which will help improve the application’s performance as well as resource utilization. It adjusts, based on demand, how many active threads are present at any time.

58. How to unit test in .NET?

Ans:

• To unit test in .NET, may use a testing framework such as MSTest, NUnit, or xUnit.
• Unit tests are developed methods where developers test small units of code against expected behavior. 
• Test projects are created together with the main application that the test project references, so can test classes. 
• The framework provides attributes to define test cases and methods to make assertions on the expected outcome. 
• Tools such as Visual Studio offer integrated testing support, including the ability to run tests and view results. 

59. What are generics in .NET?

Ans:

• Generics in .NET allow programmers to write classes, interfaces, and methods with a placeholder for the data type, enhancing the reusability of code as well as its type safety. 
• Using generics will be able to create collections and data structures that work with any kind of data without losing performance. 
• Generics help to avoid boxing and unboxing when using value types, which reduces efficiency. Compiling time checking for generic types also reduces runtime errors. 
• Common examples include List<T>, Dictionary<TKey, TValue>, and other collection classes.

60. What is the purpose of the Global Sax file?

Ans:

The Global. Sax is an ASP.NET file that holds application-level event handlers and logic. It provides a point where developers may listen for events in their application’s lifecycle. The code can go into this file, initializing some settings of the application, configuring services, or even application-wide error handling. Global. Sax allows for centralized management of application behavior, as well as allowing the registration of routes and services within an application as it starts to play a crucial role in managing the lifecycle and behavior of an application.

61. How is caching implemented in ASP.NET?

Ans:

There are various methods of caching applications in ASP.NET. In-cache can either be in-memory, distributed, or output cache. In terms of MemoryCache, let a certain amount of data remain in memory to speed things up. Can set an expiration policy; the items get automatically removed from the cache. This is output-caching where it saves the rendered HTML output of the page; hence it reduces processing time because would be rendering the page once and then have a copy to use next time.

62. What is a configuration file in .NET?

Ans:

A configuration file in .NET typically is web. Config for web applications and app. config for desktop applications. These contain application settings, connection strings, and other configurable parameters. In the XML format, configuration files are written, and one does not have to recompile the application when changing settings; instead, configuration file values can be retrieved and used at runtime with the help of the ConfigurationManager class.

63. How to connect to a database in .NET?

Ans:

• Use ADO.NET when connecting to any database in .NET; it contains classes like SqlConnection, SqlCommand, and SqlDataReader. 
• Begin by creating a connection string that says where database is located and everything concerning credentials.  Create a SqlConnection object based on that string by opening the connection. 
• With a SqlCommand can execute SQL queries or stored procedures.Data can be read using SqlDataReader or filled into a DataSet.
• Don’t forget to handle connections correctly using the statements to ensure automatic disposal.

64. What is ADO.NET?

Ans:

• ADO.NET is a part of the .NET Framework classes that permits developers to access and manipulate data coming from a wide range of sources like SQL Server, Oracle, and XML. 
• It offers two critical components the DataSet, a representing cache for in-memory data, and the DataReader, offering high-performance, read-only access to data from a data source. 
• ADO.NET supports disconnected architecture; therefore, an application can work with the data while keeping resource utilization minimum. It also includes transaction support and can interact with data that falls within the XML format.

65. What are the differences between IEnumerable and IQueryable?

Ans:

• IEnumerable is used for collections that can be enumerated forward only. It is an in-memory object and therefore quite useful for the collection that lives only in memory. 
• It is the opposite of IQueryable and is typically used for querying data from a data source LINQ typically uses a database. It supports deferred execution; that is, the query is only executed when it is needed. 
• This class will optimize the query by translating it into SQL, whereas IEnumerable will execute a query in memory. Use the IQueryable class for database queries and IEnumerable for in-memory collections.

66. What is a background worker in .NET?

Ans:

The BackgroundWorker class in .NET provides a means to run operations on a separate, dedicated thread. This is particularly useful for time-consuming tasks that should not block the main UI thread, which improves application responsiveness. It also has some support for cancellation and progress reporting, so the UI can update as the operation progresses. It is often used in Windows Forms applications for tasks like file processing or network operations.

67. What is Cross-Origin Resource Sharing (.NET)?

Ans:

CORS is an online security feature implemented within a web browser it will determine whether to provide the resource or deny the request for access based on a different origin from where the web page was served. In .NET, can configure the CORS to allow certain domains to access resources. Here’s how can implement CORS in ASP.NET application using the Microsoft.AspNetCore.Cors package, configured in Startup. Cs file. This calls for the definition of policies that detail allowed origins, methods, and headers.

68. How would implement authentication within an ASP.NET application?

Ans:

Authentication within an ASP.NET application can be implemented using built-in capabilities such as Forms Authentication, Windows Authentication, or ASP.NET Identity. For Forms Authentication, create a login page that validates user credentials and will issue a cookie to control the session. ASP.NET Identity provides a more comprehensive solution to user management, which includes roles and claims. Most of this configuration will occur in the Startup.cs file when working with authentication schemes and policies.

69. What are web forms in ASP.NET?

Ans:

• Web Forms is a framework in ASP.NET for dynamic web applications. It is a page-based model: developers could create web pages by using both HTML as well as server-side controls. 
• Each control encapsulates rendering as well as state management, which makes the development easier. Web Forms supports event-driven programming, meaning developers can respond to client events.
• While it does offer rapid development, many of today’s modern applications prefer using ASP.NET MVC or ASP.NET Core for the added control and flexibility.

70. What does the HttpContext class?

Ans:

The class HttpContext in ASP.NET captures every HTTP-related information concerning one HTTP request. It gives access to request and response data such as headers, query strings, and form data. Developers make use of HttpContext to manage session state, cookies, and application state. It serves as the connecting link between the web server and an ASP.NET application, making it possible to read and alter the data for the request/response that occurs as part of the lifecycle of a request. 

71. How to maintain state in ASP.NET?

Ans:

State management in ASP.NET is the process of holding information between multiple requests. ASP.NET provides several options for state management. View State maintains data on the client side between postbacks. Session State preserves user information on the server for the entire session, and Application State is applied to any data shared by all users. Another thing could do is use cookies to store small pieces of information unique to the user. Again, that depends on the nature of application being scalable, secure, and performant.

72. What are the types of sessions in .NET?

Ans:

• Sessions can be managed in .NET in the following ways: In-Process Session is storing session information in memory on the web server, where it has access speed but not scalability.
• Data will be stored in a different process, which permits out-of-process storage and supports scalability. SQL Server Session Session data will exist in a database, which supports durability and allows web farms. 
• Custom Session Providers can be created depending on the special storage needs. All the options have trade-offs related to performance, scalability, and complexity.

73. What is the difference between ViewBag and ViewData?

Ans:

• ViewBag and ViewData are two different methods that can be used to pass information from a controller to a view in ASP.NET MVC. 
• The only difference is that ViewData is a dictionary object that stores key-value pairs and have to typecast while extracting values. 
• ViewBag is a dynamic property. It means that the developer has to typecast nothing to access data, which makes it more developer-friendly. 
• It all depends on a dynamic type of keyword, which will lead to runtime errors if keywords are misspelled.

74. How to implement logging in a .NET application?

Ans:

Can implement logging in a .NET application using a few different frameworks, the most popular of which are Serilog, NLog, and log4net. Begin by installing a logging framework via NuGet and then doing some configuration within an application’s startup. It is possible to configure the targets for where the logs are output to include files, databases, or cloud services. Then inject the logger into classes using dependency injection. Proper logging involves logging levels, such as Info, Warn, and Error, which group messages.

75. What is the Service Locator pattern?

Ans:

The Service Locator pattern is one of the design patterns that retrieve an application’s dependency. It can be considered as a central registry issuing access to multiple services without the classes containing information about their implementation. It promotes loose coupling and makes testing easier since object creation is detached from classes that use the services. At the same time, it introduces hidden dependencies and obfuscates code.

76. What is LINQ query syntax?

Ans:

• LINQ query syntax is a way to access data from collections or databases directly within C# using a SQL-like syntax. Write queries against arrays, lists, or databases using keywords such as from, where select, and orderly. 
• Because this syntax reads more like SQL, it’s much easier to read than normal Linq with the same static type checking and IntelliSense available. 
• This is made easy and expressive because LINQ query syntax supports filtering, grouping, and sorting operations.

77. What is a data context in Entity Framework?

Ans:

• A data context in Entity Framework will act as a bridge between the application and the database that manages the connection and assists in CRUD operations. 
• The context based on changes to entities makes it possible to retrieve data efficiently and update it in real time. 
• When creating a service application using Entity Framework Code First, the data context defines how entity classes are mapped to database tables. 
• Developers would often encapsulate database logic and configurations within a class that inherits DbContext.

78. How can establish a RESTful service in .NET?

Ans:

• Building a web API of a RESTful service can be done on top of the ASP.NET core, starting with defining a controller class that extends ControllerBase. 
• Then use attributes like [HttpGet], [HttpPost], [HttpPut], and [HttpDelete] to define the endpoints and their corresponding HTTP methods. 
• The routing configuration inside Startup.cs tells ASP.NET how requests should map to controllers.  Ensure API endpoints are protected with the appropriate authentication and authorization.

79. What does a controller do in MVC?

Ans:

A Controller in the MVC (Model-View-Controller) pattern acts as a middleman between the Model and the View. The controller accepts user input, processes requests, and changes data through interaction with the Model. After processing, the controller will determine which View to return as the response. Controllers are also responsible for controlling the flow of the application. They include validation of the input and implementing the business logic.

80. What is middleware in ASP.NET Core?

Ans:

Middleware in ASP.NET Core is a piece of software that executes each request to an application. What it does is handle requests and responses, and thus it can be used in adding custom processing logic, such as authentication and loggùng as well as error handling. Middleware can be configured between lines in the Startup.cs file in the Configure method where can define the order of execution of components. Each middleware can either short-circuit the request pipeline or pass control to the next middleware.

81. How to handle file uploads in ASP.NET?

Ans:

In an ASP.NET Core application, would typically use the IFormFile interface to handle file uploads in ASP.NET. First, would create a form in HTML containing an <input type=”file”> element for this purpose. In the controller, might have an action where it accepts the uploaded file as a parameter. To save the file to an appointed directory, methods like FileStream or CopyToAsync would be used. Validate file types and sizes for security reasons. Consider also some use of middleware for handling greater uploads.

82. What does HttpClient do?

Ans:

• HttpClient is a class in the .NET Framework that facilitates the sending of an HTTP request and reception of an HTTP response from a resource identified by a URI. 
• HttpClient is ideal for calling RESTful services or APIs because it takes care of anything requiring headers in request, query parameters, and content. 
• This supports modern features like cancellation tokens and automatic handling of cookies. To avoid socket exhaustion, instantiate HttpClient once and reuse it throughout the application.

83. What are the advantages of Azure? NET.

Ans:

• There are lots of advantages to using Azure with .NET including scalability, security, and integrations of other Microsoft services. 
• Having Azure App Services, Azure Functions, and Azure SQL Database, among many more cloud services, it can be easily deployed by developers. 
• The system has also supported seamless DevOps practices using tools such as Azure DevOps, and GitHub Actions. 
• With the global infrastructure of Azure, applications may be deployed closer to users thereby improving performance. 

84. What is ASP.NET? How do implement role-based security in ASP.NET?

Ans:

• Role-based security on an ASP.NET application is usually implemented by using ASP.NET Identity. 
• The RoleManager would be used for the creation and management of those roles, while the UserManager can be used to assign users to roles. 
• The following attribute would be used within controllers or action methods to restrict access based on the user’s role.
• Also, include the role management in the Startup.cs file. This way, specific resources could not be accessed without proper authorization.

85. What is dependency inversion in .NET?

Ans:

Dependency inversion refers to the software design principle that says that high-level modules should depend on abstractions rather than concrete implementations. In the context of .NET, this can very often be fulfilled through interfaces or abstract classes, which are much more flexible and easier to test. Can replace the implementations without modifying the high-level code by inverting dependencies.

86. How to raise custom exceptions in .NET?

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To raise custom exceptions in .NET, might inherit a new exception class from the base Exception class. Can extend it further with more properties or methods to add further details about the error. Can surround application code with a try-catch block to catch the custom exception and allow for some form of graceful error handling. The user can use a logging framework to log the details of the exception.

87. How does it relate to a partial class in .NET?

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A partial class in .NET is a way of breaking the definition of a class into pieces spread across multiple files. It is also useful to organize large classes or to separate auto-generated code, such as designer files from code developed by the developer. All parts must include the keyword and be contained in the same namespace. The compiler will combine all parts into a single class during the compilation of the application.

88. How will handle application configuration settings in .NET?

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• Application configuration in .NET can be controlled by appsettings.json files in ASP.NET Core or the use of the web. 
• Config in traditional ASP.NET applications; both these store key connection strings or application-specific settings in the form of a list of key-value pairs. 
• Can use the IConfiguration interface to access application settings in ASP.NET Core.  It supports multiple sources, including JSON files, environment variables, and command-line arguments.

89. What is the role of the Task Parallel Library of .NET?

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• The Task Parallel Library, abbreviated TPL, is a .NET class library that provides public types and APIs for parallel programming. 
• Utilizing the TPL gives a strong framework for the asynchronous and parallel management of tasks to write more efficient and scalable applications. 
• TPL provides the Task class for representing an asynchronous operation and is complemented with methods, used for creating, scheduling, and managing tasks. 
• It supports parallel loops and LINQ queries for data processing. Developers can also use TPL to improve the responsiveness of an application, as well as optimize available system resources.

90. How to implement OAuth authentication in an ASP.NET application?

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Implement OAuth authentication have the choice of configuring an ASP.NET application with external authentication providers such as Google, Facebook, or Microsoft. In ASP .NET Core.OAuth package. First, need to register authentication services in Startup. Cs. Inside it, specify the client ID and secret of the provider. Implement callback methods as necessary to address authentication and get user information.