Top 25 Angular 10 Interview Questions And Answers 2021

Are you getting prepared for an Angular developer’s dream career? Or have maybe decided to shift to an independent Angular Developer career? What is a9ngular 10 interview questions? Angular still dominates the JavaScript domain and has repeatedly proven to be a befitting incentive to invest in web designers who are trying to quickly track their careers. Not surprisingly, Angular is primarily known for its ability to develop web apps with a single page that covers 3 key components-speed, agility, and a strong community to back it up. Angular is recognized as the front-end developer’s Swiss army knife. This is why Angular Certification is by far the most rigorous programming domain qualification.

Knowing the right buzzwords, learning the right technologies, and preparing the correct answers for frequently-asked Angular interview questions is essential for an Angular professional. Here’s a definitive list of the top Angular interview questions 2021 which will ensure a breeze-through to the next stage. In the article, we will look at the popular Angular 10 interview questions for the role of an Angular developer. Listed below the top 25 angular mostly asked interview questions which you may face during your AngularJS 10 interview question and answer session.


Top Angular 10 Interview Questions and Answers 2021

Angular Interview Questions Answers 2021
Angular Interview Questions Answers 2021

1. What is Angular?

Answer: Angular is a front-end, typescript based open-source web structure. It’s among the most successful JavaScript frameworks primarily upheld by Google. It serves as a platform for convenient web-based application development and enables front-end developers to curate multi-platform applications. It incorporates amazing tools such as declarative frameworks, end-to-end toolchains, dependency injection, and myriad other best practices that simplify the path to success.

2. What is AngularJS? State the differences between Angular and AngularJS.

Answer: AngularJS is a JavaScript framework that is used to make web applications rich and extensible. It operates on plain JavaScript and HTML, so no other dependencies are needed to make it function. AngularJS is suitable for single-page apps. It is essentially used to connect JavaScript particles with elements of the HTML UI.

The basic distinctions about Angular and AngularJS that you should bear in mind are these:

  • Angular has been upgraded with the AngularJS variant.
  • Close to the start on, AngularJS does not enable any mobile support and is now providing mobile support through Angular.
  • Angular uses code – ‘TypeScript’ and AngularJS uses the ‘JavaScript’ code to build a program.
  • Angular decreases the designer’s burden with its improved structure and faster, too. Whereas AngularJS makes the process more time-consuming.
  • Angular facilitates hierarchical Dependency Injection with unidirectional tree-based pattern recognition while AngularJS does not endorse the Dependency Injection principle.

3. If you use Angular as part of a larger project, so what were the benefits of that? Also, discuss the disadvantages.

Answer: Several of the benefits of using Angular within an assignment are –

  • Dependency injection support.
  • Has strong functions such as event handlers, animation, etc.
  • It endorses binding two-way data.
  • It follows the Architecture of the MVC model.
  • Additionally, supports RESTful programs and validations
  • A custom directive can be added.
  • It supports static template and angular design.
  • Interaction facilitated by client and server.


  • Angular learning requires a significant amount of time and effort.
  • Because of its size, complex SPAs may be problematic and leggy while using.
  • Dynamic applications aren’t always working possibly the best.

4. Does Angular support the nested controller? How would you distinguish between Angular and JavaScript expressions?

Answer: Yes, Angular backs the notion of nested controllers. It is necessary to define the nested controllers hierarchically for its use in the View.


Angular expression supports filters while expressions in JavaScript do not support filters.

Unlike the JavaScript expression, the angular expression does not support conditionals, loops, and exceptions.

In the HTML tags, the angular expression can be written, and JavaScript cannot be written in HTML tags.

5. What are the new features of Angular 10?

Answer: Google-developed framework update is particularly focused more on the environment than on functionality.

Chances are that Angular 10 is smaller than the previous iterations of Angular.

A completion date for the release of an Angular 10 production is yet to be set. Angular 9.0 largely became available on 6 February, followed by Angular 9.1 on 25 March.

Angular 10, a scheduled upgrade to the popular programming framework, is now underway, with two major TypeScript-based platform beta releases having arrived on April 8, 2020.

Features Of Angular 10

  • Several bug fixes were made including that of the compiler avoiding unspecified expressions in a holey array and the core avoiding a migration mistake when importing a non-existent sign.
  • The type of URL matcher will represent, in a breaking change, that it could always return zero.
  • Adding information about the dependency and ng-content selectors to metadata. This suggested compiler feature will provide additional useful metadata for resources such as the Angular Language Service, providing the ability to supply suggestions for library-defined directives/components.

6. What are the advantages of TypeScript in Angular?

Answer: In Angular the main advantages of TypeScript are:

  • Error Is Recognised Early

In Angular, TypeScript catches the errors very quickly.

  • Maintainability

Simple and convenient retain as well as using a framework supported by a full-time design team in conjunction with such a comprehensive development community is a top focus for most businesses.

  • Uniformity

The uniformity of code is an important objective to strive for in any base of code. If you or your group need to support production applications, you will realize how serious uniformity is and why it contributes to improved upkeep.

  • Modularity

Angular means sorting coding into “buckets.” Everything you create should be coordinated into one or more buckets, whether that is components, services, pipes, or directives.

7. What is MVC Architecture?

Answer: MVC stands for “Model-View-Controller.” The MVC model or “pattern” is frequently used for the development of modern interfaces.

It offers essential parts for the design of desktop or mobile programs, and also web applications. Also, MVC is one of the most regularly used industry-standard website development systems for the creation of scalable and flexible ventures.

8. What’s the Angular CLI? How would you use it?

Answer: Angular CLI simplifies the end-to-end phase of growth. Initialising, configuration, and advancement of the app will be simple and easy.

With the CLI (Command Line Interface), developers can develop ideas, add new features, and test software (unit tests and end-to-end tests) by simply entering a few simple commands. This way, both the design and implementation procedures get quicker.

9. What do you mean by Angular Directives and Dependency Injection?

Answer: Angular Directive is a typescript class that is asserted to be a @directive designer. The directives enable you to attach actions to the DOM elements, and the @directive designer provides you with added metadata to evaluate how the directives must be handled, actualized, and used during run-time.

Dependency Injection is an effective application dependency management technique. DI is a way of creating objects that depend on certain objects.

Angular has its DI structure sequence, and without Dependency Injection (DI) you really can’t even build an Angular application.

The DI system supplies dependent objects when an instance of an object is created.

10. Can you illustrate Angular Services?

Answer: Singleton objects in Angular, called services, are instantiated only once during the entire lifespan of an application. An Angular Service also includes methods for maintaining the data throughout an application’s lifetime.

Besides, Angular service’s primary intention is to arrange it and share business logic, models, as well as data and functions with different components of an Angular application as well. And any element, such as a controller or directive, can invoke the functions offered by its service.

11. What do you mean by Scope in Angular?

Answer: Scope in Angular is an object which refers to a framework of the application. It is a context for the execution of expressions. Scopes are structured in a hierarchical system that imitates the application’s DOM design. Scopes can view expressions and proliferate occurrences.

12. What do you mean by the term Digest Cycle?

Answer: Digest Cycle is a sequence of watchlist monitoring to track changes in the watch variable value. The digest cycle is sparked tacitly but we can also manually trigger it using the function $apply). 

Please note: This is one of the commonly asked angular 10 interview questions and answers for experienced developers.

13. What is HttpClient in Angular, and its benefits?

Answer: Most front-end web applications need to interact with some kind of backend services over HTTP protocol using either XMLHttpRequest or the fetch () API.

Angular offers built-in support for this via a simplified HTTP client API known as HttpClient that is based on the top of the XMLHttpRequest interface. This client is accessible from the Package @angular/common/HTTP.


  • It contains the feature of testing.
  • It offers objects of request and response.
  • We can decrypt API requests and responses.
  • Help APIs with Observables.
  • Support straightened handling of errors.

14. What is NGXS?

Answer: It’s a pattern of state management + an Angular library. NGXS acts like a single origin of facts for the state of your application, supplying the common rules of consistent mutations of a state. Also, NGXS is patterned afterwards to a CQRS pattern that is popularly enacted in libraries such as NgRx and Redux but limiting boilerplate by using the modern TypeScript characteristics like decorators and classes.

15. Distinguish among binding data one way and binding data in two ways.

Answer: Data binding in One-Way does not automatically adjust the View or UI component when the object model shifts. Users ought to write a custom code manual process to modify it each time the view alters. However, in two-way data binding, as soon as the data model shifts, the View or UI part is implicitly modified. Unlike one-way data linking, it is a synchronized method.

16. Name several tools used to check angular applications?

Answer: Karma, Angular Mocks, Mocha, Browserify, Sion are some angular testing applications.

17. Distinguish between a link and compile in Angular?

Answer: The Compile feature is used to manipulate template DOM and to gather all directives.

The link feature is used to register DOM listeners as well as DOM modulation say, and is performed once the template is copied.

18. What do you mean by the Wildcard route?

Answer: Wildcard route has a direction consisting of two (* *) asterisks that can suit any URL. If a URL does not suit any of the predefined routes it is beneficial. Developers can use a wildcard route instead of tossing error, and define a component for the same.

19. What Is a Library of Angular? Can you have your library created in Angular?

Answer: Angular library is a set of generic solutions put together by other developers for re-use. Using Angular we can create our library. These libraries can be authored as npm packages and shared. You can import a library into the device.

20. What’s the distinction here between Angular service and a factory?

Answer: In Angular, Service refers to a function that is used for the application business layer.

Services lead to a greater detachment of concerns for your application and better configure ability by letting you extract common functionality from components. Whereas factory () is a function that works similar to service but is much more powerful and flexible.

21. How do you realize about REST in Angular?

Answer: REST stands for Representational State Transfer. REST is an API (Application Programming Interface) method that works with an HTTP request.

In all this, the demanded URL defines the data that needs to be analyzed. Much further, the HTTP method then defines the various procedures that need to be done on the requested data. Thus, the APIs that follow this method is known as the RESTful APIs.

22. What’s the Angular Transclusion?

Answer: Transclusion in Angular helps to move the actual children of the Directive to a particular location within just a new template.

The ng directive implies the source file for the transclude DOM in the parent directive ( nearest) which uses the Transclusion. Attribute directives such as ng-transclude or ng-transclude-slot are primarily used only for Transclusion purposes.

23. Which one is the best out of AOT and JIT?

Answer: AOT decreases the application load and bootstrap period. It loads the pages faster, too. Any errors are often shown during the build-up of the application itself. AOT is therefore a better alternative.

24. How does the Angular Router function?

Answer: Angular router perceives a browser URL as the commands for navigating to a view generated by the client. On a website, the router is connected to the links. This way Angular recognizes when a user clicks on it, to traverse the application display to the correct tab.

25. What Is an Angular Bootstrapping Module?

Answer: The root module you bootstrap to start an application is named the bootstrap module. Each Angular framework has a module for the bootstrapping, which is often known as the AppModule. The framework to bootstrap is defined in the AppModule class.


The above ones are the most frequently asked angular 10 interview questions and answers for freshers and experienced for this latest AngularJS version.

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