Angular 8 Interview Questions & Answers [BEST & NEW] - 2020
Angular 8 Interview Questions and Answers

Angular 8 Interview Questions & Answers [BEST & NEW]

Last updated on 04th Jun 2020, Blog, Interview Questions

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Angular 8 is a powerful JavaScript framework for building dynamic web applications. Angular 8 comes with significant improvements in performance, bundle size optimization through the Ivy renderer, enhanced tooling, and better support for TypeScript. It empowers developers to create modern and feature-rich web applications with ease, making it a popular choice in the web development community.

1. Explain about Angular 8

Ans:

Angular 8 is the  client-side TypeScript based framework used to create dynamic web applications. It is more similar to its previous versions except having some extensive features. It was developed by the same team that develops AngularJS and is a complete rewrite of its first version.

2. What do you know about Ivy in Angular 8?

Ans:

Ivy is a major advancement in the Angular framework, and it was initially introduced as an opt-in feature in Angular 8. Ivy represents a complete overhaul of Angular’s rendering and change detection mechanism.

3. Why is Angular so famous in Modern Application Development?

Ans:

There are more reasons behind its popularity it unites the declarative templates, dependency injection, end to end tooling, and integrates a top performance to resolve developers’ development challenges. Angular 8 facilitates developers to develop the applications that could be live on a web and mobile, respectively.

4. What are the most prominent features of Angular 8?

Ans:

  • Angular 8 support Cross-Platform Features
  • Better Speed & Performance
  • High Productivity
  • Provide Full Development Support

5. What is Angular CDK(Component Development Kit)?

Ans:

Angular CDK consists of the tools, services, components, classes, and modules that are used by developers to build components of a web. It represents an abstraction of functionalities in Angular material themes. So, it can be used to leverage features of the Angular Material without adopting material design language.

6. Distinguish between Angular 7 and Angular 8

Ans:

Angular 7 is a slightly complex to use because it was expanded to an entire platform, including the Core framework, Angular Material, CLI, etc.

Angular 8 is comparatively smaller, faster, and simpler to use. It has Angular developer’s life easier by providing the  lot of advanced features

7. What do you know about Bazel in Angular 8?

Ans:

Bazel is a  new feature of Angular 8. It is a new build system available for a  short period and provides the  platform to make back-end and front-end with a similar tool. 

8. What is the use of the Wildcard route in Angular 8?

Ans:

 In Angular 8 Wildcard route is used to explain the route of pages.  And can make specific changes/updates while defining a  route using Wildcard.

9. Distinguish between promises and observables in Angular 8?

Ans:

Promises: Promises can deal with the  single asynchronous event at a time. Promises are always asynchronous. A Promise can  generally provide only a single value. Promises are not lazy. They can execute the  immediately after creation

Observables: The observables can handle the  sequence of asynchronous events over the  period of time. Observables are both synchronous as well as asynchronous. Observables can emit multiple values. Observables are more lazy. They can’t be an executed until subscribe to them using a subscribe() method

10. What is the usage of a Codelyzer?

Ans:

Codelyzer is the  open-source tool in Angular 8 that sits on a top of TSLint. It is used to check whether the Angular TypeScript projects follow the  set of rules or not. It also checks  an  errors in codes, not following a pre-defined rules. It contains a more than 50 rules for checking if Angular application follows the best practices.

11. How Angular 8 has enhanced performance over its previous versions?

Ans:

Singleton objects in Angular that get instantiate only once during the lifetime of an application, called services. As well as, An Angular service contains methods that maintain the data throughout the life of an application.

12. What do you mean by Ivy in Angular 8?

Ans:

Ivy is a code name for next-generation compilation and Rendering pipeline or a Rendering Engine. It was released in the  Angular 8 as Opt-in. At release of Angular 9, Ivy was intended to be the by a default rendering engine instead of  older compiler and runtime, known as a View Engine.

13. What are Pipes in Angular8?

Ans:

Pipes are the simple functions designed to accept input value, process, and return as an output, a transformed value in more technical understanding. Angular supports the several built-in pipes. However, can also create custom pipes that cater to needs.

14. What is runGuards in Angular 8?

Ans:

These pipes use the  pure functions. As a result of this, a pure pipe doesn’t use any internal state, and  output remains the same as long as the parameters passed stay the same. Angular calls  pipe only when it detects change in parameters being passed. A single instance of a  pure pipe is used throughout all components.

15. What are Impure Pipes?

Ans:

For each change detection cycle in the  Angular, an impure pipe is called regardless of change in the input fields. The Multiple pipe instances are created for pipes. Inputs passed to pipes can be mutable.

16. What is the AOT (Ahead-Of-Time) Compilation?

Ans:

  • OnInit and ngOnChanges Checks
  • Default Change Detection
  • Immutable Data and Pure Pipes
  • ChangeDetectionRef and MarkForCheck

17. What are the most important parts of Angular 8 Architecture?

Ans:

  • Modules
  • Components
  • Templates
  • MetaData
  • Data-Binding

18. What is the requirement and usage of Angular 8 components?

Ans:

Angular 8 components are essential building blocks for creating dynamic web applications. To work with them, you’ll need to have Angular CLI installed globally and set up an Angular project using the CLI. Components are typically generated using Angular CLI commands, which create a structured folder containing TypeScript logic, an HTML template, and optional CSS styles.

19. What is the usage of NgUpgrade in Angular 8?

Ans:

  • The NgModule is the class marked by a @NgModule decorator where @NgModule decorator is used to take metadata object that explains how to compile the  component’s template and how to create injector at runtime.
  • The NgModules is used to configure injector and compiler and also help to organize related things together.
  • The NgModule is used to identify  a module’s own components, directives, and pipes. It can also make some of them public, through  an exports property, to facilitate an  external components to use them.

20. What is the usage of Angular 8 ngFor Directive?

Ans:

The Angular 8 ngFor directive is used to repeat the  portion of HTML template once per each item from  iterable list (Collection). The ngFor is the  Angular structural directive and is similar to ngRepeat in the AngularJS. Some local variables like an  Index, First, Last, odd, and even are exported by a ngFor directive.

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    21. What is the usage of Angular 8 ngIf Directive?

    Ans:

    The Angular 8 ngIf directive is the  structural directive that is used to add or remove the HTML elements according to expression. The expression must return the  Boolean value true or false. And can see the functioning of a  nglf directive clearly. If expression is false, then element is removed. Otherwise, the element is inserted. It is similar to ng-if directive of AngularJS.

    22. What is data binding in Angular 8?

    Ans:

    Data Binding is one of the key concepts of the  Angular 8. It is most eminent technique which is used to link the data to the view layer. It is used to make communication between the DOM and the TypeScript code of a component.

    23. What is String Interpolation in Angular 8?

    Ans:

    String Interpolation is the  one-way data-binding technique in Angular 8. It is used to extract an output data from a TypeScript code to HTML template view layer. It shows a  data from the component to view layer in  form of curly braces.

    24. What is the Purpose of Event Binding in Angular 8?

    Ans:

    In Angular 8, event binding is a mechanism used to manage DOM events like button clicks and mouse movements. When DOM event happens (eg. click, change, keyup, keydown), it calls specified method in a component.

    25. How can you create an app in Angular 8?

    Ans:

    Set Up Angular CLI: Begin by installing Angular CLI globally on your machine using npm (npm install -g @angular/cli). 

    Generate an App: Use the Angular CLI to generate a new Angular app with the ng new command. 

    Develop Components: In Angular 8, you build your app by creating components.

    26. What is the purpose of Angular 8 forms?

    Ans:

    The main purpose of the Angular 8 forms is to handle user’s input. can also use these Angular forms in the  application to enable users to be  log in, update profiles, enter information, or perform more data-entry tasks.

    27. What is the use of reactive forms in Angular 8?

    Reactive forms use the  model-driven approach to handle form the  inputs where values constantly change over time. It uses the  explicit and immutable approach to manage the state of a form at a specific time. Each  time the changes occur to  a  form state, it returns the  new state.

    28. What benefits does using the Template-driven forms in Angular 8?

    Ans:

    • Template-driven forms are simple  to use in the application, but they are not as a scalable as Reactive forms, so they are preferred to use in a test applications for learning purposes.
    • Template-driven forms are majorly used if application requires the  very basic form and logic. It can easily be managed in template.

    29. Distinguish difference between reactive forms and Template-driven forms in Angular 8

    Ans:

    Reactive Forms

    Reactive forms are the more robust, so they are best to use. Reactive forms are scalable, reusable, and testable, so they are preferred to use in a professional websites for the industry.

    Template-driven forms Template-driven forms are best if want to add a simple form to the  application.Template-driven forms are mainly used if application requires the  more  basic form and logic. It can easily be managed in template

    30. Explain the term Angular Universal

    Ans:

    Angular Universal is the  technology that is used to render the Angular applications on a server. This process is called the SSR (server-side rendering). A simple Angular application is executed on a  browser as all Angular applications are single-page applications, so rendering always occurs on a browser.

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    31. Explain AOT in Angular 8

    Ans:

    In Angular 8, AOT stands for the Ahead-of-Time compiler. It pre-compiles the application components and templates during build process.

    32. Tell some of the features of Angular 8 which differentiate it from previous versions of Angular.

    Ans:

    • Angular 8 supports the dynamic imports for lazy routes.Angular 8 provides a feature of differential loading for all the applicable codes.
    • It also supports the features like Web Workers, Bazel, and TypeScript 3.4
    • There is an Opt-In usage sharing in Angular 8.
    • There are more NgUpgrade improvements in Angular 8.

    33. What is the use of Ivy in Angular 8?

    Ans:

    • Smaller Bundle Sizes
    • Improved Tree Shaking
    • Faster Compilation
    • Better Debugging
    • Enhanced Component Interaction

    34. What is the use of a Bazel in Angular 8?

    Ans:

    • Bazel is the  build system in Angular 8 available for the  short period.
    • It provides the  platform to make back-end and front-end services with a  same tool.
    • It allows us to build the CLI (Command Line Interface) applications quickly and easily.
    • It supports the customization and also facilitates us to draw  the graphs.
    • Formats a number to the currency format

    35. Describe the importance of WildCard Route in Angular 8.

    Ans:

    Angular 8 WildCard Route does can extremely important job of matching the URLs as instructions to get client-generated view. It sets a route when URL which is requested does not match any router paths. In a nutshell, WildCard Router sets or explains  the routes of the pages in Angular 8.

    36. Why are template-driven forms used in the Angular 8?

    Ans:

    Angular 8 Template-driven forms are to add simple forms to applications where scalability is not an issue. They are easy to use but not as scalable as Reactive forms.

    37. How can you check the type of value assigned to a given variable in Angular 8?

    Ans:

    In Angular 8, type of checks can be used to check the type of value assigned to the  given variable. Moreover, can also test the value assigned to an object by using the type of checks in version 8 of Angular.

    38. Why does the incremental DOM have a low memory footprint in Angular 8?

    Ans:

    Each  time we re-render, a Virtual DOM creates a  tree from scratch. But incremental DOM needs no memory to re-render a view as long as DOM isn’t changed, and memory has to be allocated only when DOM nodes are to be added or deleted. The size of memory allocation is proportional to  the size of change in DOM. 

    39. Define Angular TestBed in the context of Angular 8.

    Ans:

    The Angular TestBed or ATB is the  higher-level testing framework exclusively for the Angular, which helps us smoothly test behaviors that depend on a Angular Framework. It provides the  dynamically-constructed Angular test module that emulates  the Angular @NgModule.

    40. What is Redux in context of Angular 8?

    Ans:

    Redux is a technique for managing asynchronous applications’ state and making them easier to maintain. For application state and unidirectional flow of data change, it offers a single source of truth. 

    41. What utility functions provided by RxJS in Angular 8?

    Ans:

    Some utility functions are  RxJS library provides the  help us to create and work with the observables are filtering streams, mapping the values to various types, creating the multiple streams, iterating through the values in stream, and converting a code into the  observables for async operations.

    42. What is the Angular CLI?

    Ans:

    The Angular CLI is a command-line tool made available by the Angular team to ease and streamline certain development activities while working with Angular apps. It is a sophisticated tool that allows developers to more easily create, build, test, and manage Angular applications.

    43. What are the different types of data binding in Angular 8?

    Ans:

    • Interpolation
    • Property binding
    • Event binding
    • Two-way data binding

    44. What are templates in Angular?

    Ans:

    In Angular, a template is  the  form of HTML that tells Angular how to render  component. A template is the  declarative way to explain  a component’s view. It can include the HTML, CSS styles, and Angular directives.  

    45. What are the advantages of the AOT Compilation?

    Ans:

    • Improved Performance
    • Better Security
    • Better Developer Experience
    • Better SEO
    • Reduced Load on the Client

    46. What is Interpolation in the Angular 8?

    Ans:

    Angular 8 interpolation is the  feature that allows us to insert a dynamic values into template. It is the  one-way data binding technique that allows us to display the value of component’s property in a  template.

    47. What are the lifecycle hooks available in Angular 8?

    Ans:

    ngOnChanges(): This hook is called when input binding  a value changes, it is used for an  Angular change detection. 

    ngOnInit(): This hook is called after first ngOnChanges() and is often used for an  initializing the component. 

    ngDoCheck(): This hook is called during an every change detection run and is used for a custom change detection. 

    ngAfterContentInit(): This hook is called after component’s content has been initialized and is used for an interacting with projected content. 

    48. What is the difference between the ngOnInit hook and constructor?

    Ans:

    The constructor is standard JavaScript method called when  object is created. The constructor is called before  component’s data-bound properties are be initialized, so it cannot be used to access or modify  component’s template or state. 

    On the other hand, ngOnInit is the  Angular lifecycle hook that is called after component’s data-bound properties have been initialized. It is invoked by  a Angular’s change detection mechanism after first round of change detection is completed, this makes sure that component and its children are fully utialized, and inputs are set.  

    49. What is service in Angular 8?

    Ans:

    In Angular 8, Service is the class that encapsulates a some common business logic or functionality that must be reused throughout application.

    50. What is dependency injection in Angular?

    Ans:

    Dependency injection in a Angular 8 is the  technique for creating and managing instances of an objects that component depends on. These objects, known as a dependencies, are typically services or the other types of classes. Rather than creating dependencies directly within a  component, they are instead provided to component through the  process called injection.

    51. Explain different types of directives in Angular 8

    Ans:

    • Components Directives
    • Structural directives
    • Attribute directives

    52. Define Angular Material

    Ans:

    Ans:

    Templates in Angular are written with HTML that contains Angular-specific elements and attributes. These templates are combined with information coming from the model and controller which are further rendered to provide the dynamic view to the user.

    53. What are Angular Pipes used for?

    Ans:

    In Angular, pipes are a technique to alter data before presenting it in a template or user interface by applying a set of pre-defined or custom logic to the information. Data formatting for display and basic data processing are done via pipes.

    54. When should we use inline templates and external templates in Angular 8?

    Ans:

    Using an inline template is useful when: 

    • The template is more relatively small and simple, as it can make component class definition more concise and easier to read. 
    • Want to take advantage of a syntax highlighting, auto-completion and error checking features of a code editor 

    Using an external template is beneficial when: 

    • The template is large or complex, as it can make component class definition more readable and maintainable by moving DOM code to template file. 
    • want to reuse template for the multiple component

    55. How can import a third party libraries in Angular?

    Ans:

    • Install library using npm by running a command npm install in root of project.
    • Add the following line of code to the beginning of the app.module.ts file to import the library: import library-name> from ‘library-name>.
    • Include a library in the imports array of the @NgModule decorator.

    56. What Programming languages is used for a development of Angular 8 Application?

    Ans:

    Angular utilizes TypeScript, which is a superscript of JavaScript. Typescript allows us to write JavaScript as a robust type of language that allows us to quickly detect and troubleshoot mistakes.

    57. Explain some of use cases of Angular 8

    Ans:

    • Building Large Enterprise Applications 
    • Progressive Web Applications (PWA) 
    • Migrating old legacy Application to Modern Framework 

    58. What are the Custom elements?

    Ans:

    Custom elements (or Web Components) are a feature of the Web Platform that extends HTML by allowing the definition of a tag whose content is produced and controlled by JavaScript code. The browser maintains the CustomElementRegistry of defined custom elements, which maps instantiable JavaScript class to HTML tag.

    59. What are the utility functions provided by RxJS?

    Ans:

    • Converting an existing code for async operations into the observables
    •  Iterating through a values in a stream
    • Mapping values to the different types
    • Filtering streams
    • Composing the multiple streams

    60. What is the difference between AOT and JIT?

    Ans:

    Ahead of Time (AOT) compilation converts a code during the build time before browser downloads and runs that code. This ensures the faster rendering to the browser. To specify the AOT compilation, include the –aot option with ng build or ng serve command. 

    The Just-in-Time (JIT) compilation process is the way of compiling computer code to the machine code during execution or run time. It is also known as a dynamic compilation. JIT compilation is a default when run ng build or ng serve CLI commands.

    61. Why should ngOnInit be used?

    Ans:

    Mostly use ngOnInit for all the initialization/declaration and avoid stuff to work in a constructor. The constructor should only be used to initialize the class members but shouldn’t do actual “work”. So should use the constructor() to setup Dependency Injection and not much else. ngOnInit() is a better place to “start” – it’s where/when components’ are bindings are resolved.

    62. Why does incremental DOM have low memory footprint in Angular 8?

    Ans:

    Each time we re-render, Virtual DOM creates the tree from scratch. But incremental DOM needs no memory to re-render the view as long as DOM isn’t changed, and memory has to be allocated only when a DOM nodes are added or deleted. The size of memory allocation is also proportional to size of change in DOM. 

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    63. Define the Angular TestBed in a context of Angular 8.

    Ans:

    The Angular TestBed or ATB is more higher-level testing framework exclusively for an Angular, which helps us to smoothly test behaviors that depend on a Angular Framework. It provides the dynamically-constructed Angular test module that emulates Angular @NgModule.

    64. What command will be used to load and run any Angular Application?

    Ans:

    To load and run an Angular application, you can use the Angular CLI (Command Line Interface). The primary command to start an Angular application is:

    • ng serve

    65. What are the Annotations in Angular?

    Ans:

    Annotations in Angular are used for creating the annotation array. They are metadata set on a class that is used to reflect Metadata library.

    66. Differentiate between the Angular and AngularJS

    Ans:

    • AngularJS : Supports the Model-View-Controller design. Not supported by a mobile browsers . @routeProvider is used to provide a routing information.
    • Angular :Uses the components and directives . Supports all the popular mobile browsers . @Route configuration is used to define the routing information

    67. What is Lazy Loading?

    Ans:

    Lazy loading is a technique used in web development, including in Angular applications, to improve performance and reduce initial load times. It involves loading certain parts of an application only when they are needed, rather than loading everything upfront when the application is first accessed.

    68. Explain the term Pure Pipes

    Ans:

    In Angular, pure pipes are a specific kind of pipe that are intended to be “pure” in the sense that they modify data without having any side effects and are only performed when their input data changes.

    69. What are Angular directives?

    Ans:

    Angular directives are special markers in the HTML code that tell the Angular framework to do something to a DOM element or a portion of the DOM. They are a fundamental building block in Angular applications and allow you to extend the HTML vocabulary with custom behavior and functionality.

    70. What is ngModule?

    Ans:

    NgModules are containers that reserve the  block of code to the  application domain or workflow. @NgModule takes metadata object that generally describes a way to compile template of a component and to generate injector at runtime. In addition, it identifies a  module’s components, directives, and pipes, making some of them public.

    71. What filters are there in Angular?

    Ans:

    • date – Format date to a specified format.
    • filter – Select the subset of items from an array.
    • Json – Format an object to JSON string.
    • limitTo – Limits an array/string, into the specified number of elements/characters.
    • lowercase – Format a string to the lowercase.

    72. Define view encapsulation in Angular

    Ans:

    View encapsulation in Angular refers to a mechanism that isolates the styles and behavior of a component’s view (HTML template and associated CSS) to prevent unintended style conflicts and maintain component modularity.

    73. What are controllers?

    Ans:

    AngularJS controllers control a data of AngularJS applications. They are regular for JavaScript Objects. The ng-controller directive explains the application controller.

    74. What do you understand by scope in Angular?

    Ans:

    The scope in Angular binds HTML, i.e., the view, and JavaScript, i.e., the controller. It as expected is object with the available methods and properties. The scope is available for both the view and controller. When make a controller in Angular, and pass the $scope object as an argument.

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    75. What is RxJS?

    Ans:

    “Reactive Extensions for JavaScript,” or RxJS, is the name of a library for reactive programming that uses Observables. It gives you a strong means to interact with asynchronous data streams and gives you the ability to compose and control them declaratively.

    76. What is ngOnInit?

    Ans:

    ngOnInit is lifecycle hook and callback method that is run by a Angular to indicate that component has been created. It takes the no parameters and returns void type.

    77. What is Eager and Lazy loading?

    Ans:

    Eager loading is a  default module-loading strategy.A Feature modules under the Eager loading are loaded before application starts. This is typically used for a small size applications.

    Lazy loading dynamically loads  feature modules when there is a  demand. This makes application faster. It is used for a bigger applications where all modules are not required at start of the application.

    78. What type of DOM does the Angular implement?

    Ans:

    Angular uses a regular DOM. This updates entire tree structure of HTML tags until it reaches a data to be updated. However, to ensure that speed and performance are not affected, Angular implements the  Change Detection.

    79. Why are client-side frameworks like a Angular introduced?

    Ans:

    Client-side frameworks like an Angular were introduced to provide more responsive user experience. By using the  framework, developers can create a web applications that are more interactive and therefore provide better user experience.

    80. How does an Angular application work?

    Ans:

    An Angular application is the Single Page Application, or SPA. This implies that a whole application is contained within a single page, and all resources (HTML, CSS, JavaScript, and so on) are loaded when the page is initially loaded.  Angular uses Model-View-Controller, or MVC, architecture pattern to manage data and views.

    81. Explain components, modules and services in Angular.

    Ans:

    Angular’s components form the user interface, while modules organize related components and services, promoting maintainability and testability through data sharing and logic separation.

    82. How does Angular expressions different from JavaScript expressions?

    Ans:

    One major difference between the Angular expressions and JavaScript expressions is Angular expressions are compiled while  the JavaScript expressions are not. This means that Angular expressions are much efficient since they are  already pre-processed. Additionally, Angular expressions can access  the scope properties while the JavaScript expressions cannot. Finally, Angular expressions support a some additional features like  filters and directives which aren’t available in a JavaScript expressions.

    83. What does Angular by default, uses client-side rendering for its applications?

    Ans:

    This means Angular application is rendered on a client-side — in user’s web browser. Client-side rendering has a number of the  advantages, including the improved performance and better security. However, there are some drawbacks to using  the client-side rendering, as well. One of the biggest drawbacks is can make  the application more difficult to debug.

    84. How do share data between components in the Angular?

    Ans:

    Sharing data between the  components in Angular is simple and easy. To share a data, all need to do is use Angular CLI to generate new service. This service can be injected into the any component and will allow components to share data.

    85. How does catchError work?

    Ans:

    The catchError operator in RxJS is used to gracefully handle errors that may occur when working with observables. It allows you to intercept and replace an error with a new observable or handle the error in a custom way.

    86. Explain MVVM architecture.

    Ans:

    MVVM architecture is architectural pattern used mainly in a software engineering. It stands for a Model-View-ViewModel. MVVM is the variation of the traditional MVC (Model-View-Controller) software design pattern. The main difference between two is MVVM separates user interface logic from  a business logic, while MVC separates a  data access logic from business logic.

    87. Describe parameterized pipe

    Ans:

    A parameterized pipe in the Angular is a pipe that accepts one or more arguments, also known as a parameters. Pipes can transform data in the Angular templates, and parameterized pipes allow to customize transformation based on a specific requirements. By passing the parameters to a pipe can modify its behavior and apply various  transformations to the data.

    88. What are class decorators?

    Ans:

    A Class decorators in the Angular are a type of decorator that can be applied to the class declaration. They are used to modify behavior of the class or add additional functionality. Class decorators are expained  using the @ symbol followed by decorator name and are placed immediately before  class declaration.

    89.What are Method decorators?

    Ans:

    Method decorators in the Angular are decorators that can be applied to the methods within a class. They are used to modify behavior of the method or add additional functionality. Method decorators are explained  using the @ symbol followed by  a decorator name and are placed immediately before method declaration.

    90. What are property decorators?

    Ans:

    Property decorators in an  Angular are decorators that can be applied to a class properties. They are used to change  behavior of the property or add additional functionality. Property decorators are explained using @ symbol followed by decorator name and are placed immediately before a property declaration.

    91. Explain router links

    Ans:

    Router links in the Angular are used for navigation within application. They are explained  using the routerLink directive and provide a way to navigate to various  routes or components.

    92. What exactly is the router state?

    Ans:

    The router state in the Angular represents current state of Angular router. It contains information about current route, including URL, route parameters, query parameters, and  the other related data. The router state can be accessed and manipulated using Angular Router service.

    93. What does Angular Material mean?

    Ans:

    Angular Material is the  UI component library for an Angular applications. It provides the  set of pre-built and customizable UI components, like  buttons, forms, navigation menus, and dialog boxes, that follow Material Design guidelines. Angular Material simplifies a process of building consistent and visually appealing user interfaces in  the Angular.

    94. Define transpiling in Angular

    Ans:

    Transpiling in the Angular refers to process of converting TypeScript code into the JavaScript code that web browsers can execute. Since browsers can only run on  JavaScript, the TypeScript code needs to transpiled into the  JavaScript before it can executed.

    95. What are HTTP interceptors?

    Ans:

    HTTP interceptors Angular are feature that allows to intercept HTTP requests and responses globally. Interceptors are  provide a way to modify or handle  the HTTP requests and responses at a centralized location before reach the server or client.

    96. What is Change Detection?

    Ans:

    Change Detection in Angular is the  mechanism that determines when and how to update user interface based on changes in application’s data model. Angular uses the  tree of change detectors to track changes in a component properties and update DOM accordingly.

    97. How does SASS into an Angular project?

    Ans:

    • Install node-sass package by running a command npm install node-sass –save-dev.
    • Update angular.json file in  the  project’s root directory.
    •  Locate styles property under architect > build > options.
    • Change  file extension from .css to .scss to indicate that  are using SASS.
    •   Rename existing CSS files to the  SCSS files (e.g., styles.css to styles.scss).
    • Restart Angular development server for changes to take effect.

    98. What happens when use a script tag within a template?

    Ans:

    Using  a script tag within an Angular template is not recommended practice. Angular templates are intended for explaining  the structure and layout of the user interface, and including the scripts directly within the template goes against separation of concerns principle.

    99. How do deal with errors in observables?

    Ans:

    When dealing with an errors in observables in Angular, catchError operator can be used to handle and recover from an errors. This operator allows to provide the  fallback value or execute alternative logic when error occurs.

    100. What is the purpose of ViewChild and ViewChildren in Angular, and how do they differ?

    Ans:

    A decorator and functionality in Angular called ViewChild lets you access and work with a child component, directive, or DOM element from its parent component. When interacting with elements or components that are a part of your component’s template, it is very helpful.

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