Top Angular Interview Questions and Answers 2025

Popular Angular Interview Questions and Answers

We have accompanied sets of angular questions below that are vital for interview preparation. The reason most of the candidates fail at the first attempt is the lack of preparation to go through the common interview questions in angular. Strategic preparation and confidence are key to winning over any interview.

These are top Angular questions and answers which you can look at for a better understanding of the subject; you can also take a look at Advanced Angular Interview Questions Set 1, Set 2, and Set 3 as well.

Angular Interview Questions and Answers – Set 1

To get a good grasp of the entire framework, the interview questions in angular to face might seem endless. But, here is the trick! It’s always a wise move to start with basic angular questions.

Here are the basic Angular Interview Questions and Answers,

 

1) What do you mean by Angular?

Angular states the open-source framework of the web application. The framework is TypeScript based, and Google maintains as well as manages it.

The framework is even developed by Google itself. Angular is famous for offering the most powerful and efficient way of developing completely web-based front-end applications.

The framework manages the integration of numerous features such as declarative templates, dependency injections and a lot more to count. These features set the ground for facilitating the development of web applications.

 

2) Why is the Angular framework inclined on the client-side?

Back in the day, there were many frameworks like jQuery and VanillaJS which allowed the developers to create dynamic websites. But with time, the websites have inculcated a large number of features and various functionalities.

This becomes quite a task for the developers who are in charge of maintaining the code. Along with this situation, jQuery does not provide any provision about the data handling facility meant across the view.

In all these situations, Angular comes to the rescue as it solves the problem and provides the platform for the developers to divide the complex code into smaller fragments. These fragments are named the Components of the Angular.

The reason for Angular being a client-side platform is that it permits to development advanced web applications much faster than VanillaJS used to do. The advanced web applications are like SPAs.

 

3) State the different features of the Angular framework. 

Angular has many features and proves to be an ideal framework. The features of Angular framework are as follows:

- Angular gives the option for creating an accessible application with the help of components enabled by ARIA, which are built on a unique infrastructure, present along with developer guide. 

- Angular also helps in supporting the interface tools in the command line. These particular tools work for adding different components, creating testing, many instant deployments and a lot more. 

- It also gives scope for creating very complex and difficult animation timelines using many little codes. It gives a chance for high performance by using its intuitive API.

- The framework can also build an efficient as well as powerful desktop. It can also create a progressive web application which is native.

Angular also supports the building of various mobile applications. It uses the capabilities of various modern web platforms to create high performing, and progressive web applications that have an offline facility. 

- Angular is well known for converting different templates to create codes that are highly optimized. 

- The Angular applications have a component router, which makes it possible for the applications to load very quickly. The component router provides a facility for splitting the code automatically, as a result of which the code required by the user is loaded to render the views.   

- It has famous code editors along with IDEs, which makes various possible operations like code completion and error detection.

 

4) Mention the different advantages associated with the Angular framework in comparison to other frameworks available. 

Angular provides the features which are out of the box. Its uniqueness provides great benefits. There is the alignment of various important built-in features on one platform so that no individual has to search for it differently.

It also uses HTML, which helps in rendering the user interface of a particular application in the form a declarative language. This method makes it easier for individuals to use than in the case of JavaScript.

Google is very certain when it comes to sticking with Angular for long-term purposes. It is even interested in developing its ecosystem, providing long-term help and support to the Angular framework. 

 

5) Is it possible to make a particular Angular application which can render service on the server-side of the application?

Yes, it is possible to do the above-mentioned with the help of Angular Universal. This technology makes it possible for Angular to render the various services on the server side.

The Angular Universal provides certain benefits like providing a great experience to the users, allowing them the capability to view the app instantly.

It also ensures that the required content is present on different individual search engines, which gives scope for a great SEO. The browsers get access to the render pages as soon as a result of which the server-side of the application loads very fast.

Angular Interview Questions and Answers – Set 2

This section of angular questions relates to more technical and practical topics. A candidate will have to logically determine the angular questions, answering in the most precise way as possible.

To tackle responses in the most elaborative way, one must familiarize oneself with the interview questions in Angular and have coding knowledge.

Let’s take a look at some technical Angular Interview Questions and Answers.

 

1) What do you mean by dependency injection?

The dependency injections create the core concept responsible for Angular. It is a design pattern of applications that is formulated by Angular.

These dependencies are the services having various functionalities. The other components, as well as the directives that are present in the application, sometimes require these particular functionalities.

Angular makes the mechanism of injecting the dependencies into various components and directives smooth.

 

2) What do you understand about MVVM architecture? Explain in brief. 

The MVVM architecture is responsible for removing the tight coupling present between the various components.

The architecture has three parts: nameless, model, view and ViewModel. The children can have the references present in the observables rather than their parents in the case of this architecture. 

The first part is the Model. It handles the representation of different data present and the business that concerns the logic of the application.

It is known to contain the entire structure of the particular entity. The business logic present in the model consists of different data sources, repositories, and model classes. 

The second part of the architecture is the View. It consists of the user interface code ad is the visual layer of the particular application in context.

It sends the user action to the third part, i.e., the ViewModel. The ViewModel does not give a direct response after getting the user action. The view has to subscribe to the set of observables to get the response that the ViewModel sends to it. 

The last and final part is the ViewModel. It proves to be the abstract layer of the complete application which bridges the gap between the view and the business logic or the model.

It does not have a direct connection with the view and has no idea about the view using it. The data binding connects both these parts, so when change happens between these two parts, it results in the change in the data that is present in the model.

One of the frequent interview questions in angular that should not be skipped.

 

3) What do you mean by Ahead-Of-Time or AOT compilation?

There are certain components and different templates in the Angular application, which is difficult for the browser to understand.

So, the compilation of these Angular applications becomes quite necessary for running these applications in different browsers. The above-mentioned compiler takes up the data in JS code and then compiles it to produce some other JS code.

This method defines the AOD compilation, which occurs once in case of every occasion for an individual user. The Angular provides access to two different types of compilations, namely, the Just-In-Time compilation and the Ahead-Of-Time compilation.

 

 4) State the various advantages of the AOT compilation. 

- This compilation provides an opportunity for fast rendering of the application. The compilation of the application takes place before the app gets inside the browser.

The browser rende4r the executable code immediately after the compilation of the application. 

- The compiler works with the HTML and the CSS files associated with the application. This promotes the elimination of the AJAX requests to a great extent for these particular source files. 

- The compiler makes it proportionately easy to detect and handle the errors amidst the building phase. 

- The AOT compiler does its work by adding the HTML and other templates inside the JS files, which gives a chance to put no extra HTML files that can be read.

This process takes place before the application is made to run in the browser that it is present in. The compiler, in turn, proves great security to the application by doing its designated work and turns out to be a great advantage.

 

5) How can you explain the various services in Angular?

The services are the singleton objects present in Angular. These services get instantiated just once in the complete lifetime of the application in view.

There are methods present in the Angular services which make the maintenance of the data possible throughout the lifespan of the application. The primary nature of the service includes the organization and the sharing of different business logic as well as models with the components of the Angular application. 

Any Angular component can invoke the function that the Angular service offers.

 

Angular Interview Questions and Answers – Set 3

Most of the interview questions in angular are validated by expert professionals, it evaluates candidates' level of intellectual fit for their organization. The angular questions below discuss beginner to advanced level interview questions in angular.

Let’s take a look at some descriptive Angular Interview Questions and Answers.

 

1) What are the common advantages that one can get by using Angular?

The Angular contains the ability to add the custom directive. It provides extraordinary community help and support. It also works towards facilitating the client and the server communication for better understanding.

The Angular consists of various strong features like animation and even more to count. It has an MVVM pattern of architecture. Angular even supports the static and the Angular template. It facilitates data binding in a two-way manner.

 

2) What are the disadvantages linked to Angular?

The presence of complex SPAs may create some sort of inconvenience, and their use can lag because of their size.

The various dynamic applications present in Angular may not always perform well with efficiency.

The skills associated with Angular take up a good amount of time and great effort to learn and understand. It may seem difficult to some, and not having complete and detailed knowledge about the topic can create chaos. 

These top Angular interview questions and answers are a part of the ocean of various possible Angular interview questions. These are the most common Angular interview questions, which can perfectly signify the complete interview procedure and justify the topic concerned.

Here ends the set list of Angular Interview Questions and Answers. Getting prepared with the best Angular interview questions and answers gives aspiring candidates a boost in their confidence that they can get through the interview process effectively.

 

Angular Interview Questions for Beginners

Preparing for an Angular interview? This covers key concepts like Directives, AOT Compilation, Components, Pipes, Lifecycle Hooks, and View Encapsulation with practical examples. Understand how Pure and Impure Pipes, String Interpolation, and Template Statements work, along with the role of NgModules in structuring an application. Master these Angular fundamentals to confidently ace your interview.

1) What are Directives in Angular?

Directives are instructions to the DOM that change its behavior or appearance. Example:

- Structural Directives (*ngIf, *ngFor, *ngSwitch)

- Attribute Directives (ngClass, ngStyle)

- Custom Directives (User-defined behavior extensions)

 

2) What is AOT compilation? What are its advantages?

Ahead-of-Time (AOT) Compilation compiles Angular HTML and TypeScript code before the browser loads it.

Advantages:

- Faster rendering

- Smaller bundle size

- Better security

- Improved error detection

 

3) What are Components in Angular?

Components are the building blocks of an Angular application. They contain:

- Template (HTML) – UI representation

- Class (TypeScript) – Business logic

- Styles (CSS/SCSS) – Appearance

 

4) What are Pipes in Angular?

Pipes transform data before displaying it in the UI. Example: | uppercase
Common pipes: DatePipe, CurrencyPipe, PercentPipe

 

5) What are Pure Pipes?

Pure pipes return the same output for the same input and do not detect changes in object properties unless the reference changes.

@Pipe({ name: 'uppercasePure', pure: true })

export class UppercasePurePipe implements PipeTransform {

  transform(value: string): string {

    return value.toUpperCase();

  }

}

 

6) What are Impure Pipes?

Impure pipes execute on every change detection cycle, even if the input data hasn't changed.

@Pipe({ name: 'randomImpure', pure: false })

export class RandomImpurePipe implements PipeTransform {

  transform(value: number): number {

    return Math.random() * value;

  }

}

 

7) What is an ngModule?

NgModule is a decorator that defines an Angular module, which organizes components, directives, and services. Example:

@NgModule({

  declarations: [AppComponent],

  imports: [BrowserModule],

  bootstrap: [AppComponent]

})

 

8) What are filters in Angular? Name a few of them.

Filters (in AngularJS) modify data in templates. In Angular, pipes replace filters. Examples: date, currency, lowercase, uppercase.

9) What is view encapsulation in Angular?

It controls how component styles affect the application.
Modes:

- Emulated (default) – Styles apply only to the component.

- Shadow DOM – Uses native browser shadow DOM.

- None – Styles apply globally.

 

10) What are controllers?

In AngularJS, controllers handle logic. In Angular (2+), controllers are replaced by components.

 

11) What do you understand by scope in Angular?

In AngularJS, $scope links the controller and view. In Angular (2+), the scope is replaced by components with their own encapsulated data.

 

12) Explain the lifecycle hooks in Angular.

Lifecycle hooks allow execution at different component stages.
LifeCycle Hooks:

ngOnChanges() – Called when input properties change.

ngOnChanges(changes: SimpleChanges) {

  console.log('Input changed:', changes);

}

 

ngOnInit() – Runs once after component initialization.

ngOnInit() {

  console.log('Component initialized');

}

 

ngDoCheck() – Runs on every change detection cycle.

ngDoCheck() {

  console.log('Change detection running');

}

 

ngAfterContentInit() – Runs after content projection () initializes.

ngAfterContentInit() {

  console.log('Content projected');

}

 

ngAfterContentChecked() – Runs after projected content is checked.

ngAfterContentChecked() {

  console.log('Projected content checked');

}

 

ngAfterViewInit() – Runs after component’s child views initialize.

ngAfterViewInit() {

  console.log('View initialized');

}

 

ngAfterViewChecked() – Runs after child views are checked.

ngAfterViewChecked() {

  console.log('View checked');

}

 

ngOnDestroy() – Runs before the component is destroyed.

ngOnDestroy() {

  console.log('Component destroyed');

}

 

13) What is String Interpolation in Angular?

String interpolation {{ }} is used to embed expressions in templates.

 

14) What are Template statements?

They respond to user events within templates.

Angular Interview Questions for Intermediate

Looking to advance your Angular knowledge? This covers essential Angular Interview Questions for intermediate developers, including AOT vs. JIT Compilation, Dependency Injection, Promises vs. Observables, Eager vs. Lazy Loading, and MVVM Architecture. Learn how Angular Components, Services, and Modules interact, explore Template-driven vs. Reactive Forms, and understand how data sharing works using @Input(), @Output(), and RxJS. Get a solid grasp of Angular’s Virtual DOM, client-side rendering, and Bootstrap integration to enhance your expertise and confidently tackle technical interviews.

1) What is the difference between AOT and JIT?

AOT (Ahead of Time)	JIT (Just in Time)
Compiles at build time	Compiles in browser
Faster execution	Slower execution
Smaller bundle size	Larger bundle size

 

2) Explain the @Component Decorator.

The @Component decorator defines an Angular component:

 

@Component({

  selector: 'app-root',

  templateUrl: './app.component.html',

  styleUrls: ['./app.component.css']

})

 

3) What are Services in Angular?

Reusable logic providers used for API calls, state management, etc.

Singleton Objects – Services are instantiated once and shared across components.

Dependency Injection – Services are injected into components using @Injectable().

Encapsulate Business Logic – Used for API calls, state management, and shared data.

 

4) What are Promises and Observables in Angular?

- Promise – Handles a single asynchronous event.

- Observable – Handles multiple values over time.

 

5) What is ngOnInit? How is it defined?

A lifecycle hook executed after component initialization:

ngOnInit() {

  console.log("Component Initialized");

}

 

6) How do you use ngFor in a tag?

ngFor is used as a structural directive directly within an HTML tag to iterate over a collection (like an array) and render that tag for each item in the collection.

*ngFor="let item of items">{{ item }}

 

7) What are Template and Reactive forms?

- Template-driven forms – Uses HTML-based approach.

- Reactive forms – Uses TypeScript-based form controls.

 

8) What is Bootstrap? How is it embedded into Angular?

Bootstrap is a UI framework. It can be added using npm install bootstrap and imported in angular.json.

 

9) What is Eager and Lazy Loading?

- Eager Loading – Loads modules at startup.

- Lazy Loading – Loads modules on demand.

 

10) What type of DOM does Angular implement?

Angular uses a Virtual DOM, updating only changed elements.

 

11) Why were client-side frameworks like Angular introduced?

- Faster Rendering – Reduces server load by handling UI updates on the client side.

- Single-Page Applications (SPAs) – Enables smooth, dynamic page updates without reloading.

- Better User Experience – Provides interactive and responsive UI.

 

12) How does an Angular application work?

• Modules (NgModule) – Organizes the application into functional parts.

• Components (@Component) – Defines UI and behavior.

• Templates & Directives – Bind data to HTML and manage DOM manipulation.

• Services & Dependency Injection – Share logic and data across components.

• Routing (RouterModule) – Manages navigation between views.

 

13) Explain Components, Modules, and Services in Angular.

- Components (@Component) – Defines UI and logic for a view.

- Modules (@NgModule) – Groups related components, services, and directives.

- Services (@Injectable) – Handles business logic, API calls, and shared data.

 

14) How are Angular expressions different from JavaScript expressions?

- Angular Expressions ({{ value }}) – Used in templates, do not allow loops, assignments, or function calls.

- JavaScript Expressions (console.log(value)) – Can include complex logic, loops, and function calls.

 

15) Angular, by default, uses client-side rendering for its applications.

Yes, Angular renders content in the browser (client-side) using JavaScript, updating the UI dynamically without requiring full page reloads. However, server-side rendering (SSR) using Angular Universal is available for SEO and performance optimization.

 

16) How do you share data between components in Angular?

- @Input() / @Output() – Parent to Child (@Input()), Child to Parent (@Output()).

- Service with Subject (RxJS) – Centralized state sharing.

- Local Storage / Session Storage – Persistent data across components.

 

17) Explain the concept of Dependency Injection.

- Design Pattern – Provides dependencies instead of creating them manually.

- Singleton Services – Services are instantiated once and shared across components.

Example:

constructor(private dataService: DataService) {}

 

18) Explain MVVM Architecture.

- Model (M) – Manages data and logic.

- View (V) – Handles UI representation.

- ViewModel (VM) – Acts as a bridge, binding data between Model and View using two-way binding.

 

 

 

Angular Interview Questions for Experienced

This covers advanced Angular interview questions for experienced developers, focusing on RxJS, HTTP Interceptors, Change Detection, and Angular Material. Learn how Class, Method, and Property Decorators enhance functionality, how Parameterized Pipes transform data, and how Router State and Router Links work for navigation. Understand Transpiling in Angular, the role of Bootstrapping Modules, and how Change Detection Strategies (Default & OnPush) optimize performance. Master these advanced Angular concepts to tackle complex development challenges and ace technical interviews.

 

1) What are RxJS in Angular?

Reactive Extensions for JavaScript (RxJS) – A library for handling asynchronous data.

Observables – Handle events, HTTP calls, and state management.

Operators – Transform and manipulate data streams (e.g., map, filter).

 

2) What exactly is a parameterized pipe?

A pipe that takes arguments to transform data dynamically.

Example:

Formatting a date with a date pipe.
{{ today | date:'fullDate' }}

 

3) What are class decorators?

Used to define Angular classes like components, services, modules.

Example:

@Component({

  selector: 'app-example',

  templateUrl: './example.component.html'

})

export class ExampleComponent {}

 

4) What are Method decorators?

Used to decorate class methods to enhance functionality.

Example:

class Example {

  @HostListener('click') onClick() {

    console.log('Clicked!');

  }

}

 

5) What are property decorators?

Used to bind data to properties in components.

Example:
export class ChildComponent {

  @Input() childData: string;

}

 

6) What are router links?

Used for navigation in Angular routing.

Example:

Go to Home

 

8) What exactly is the router state?

Represents the current route, parameters, and query strings.

Example:

Accessing route params:
this.route.snapshot.paramMap.get('id');

 

9) What does Angular Material mean?

• UI component library for Angular applications.

• Provides ready-made buttons, dialogs, toolbars, forms, grids for modern UI.

 

10) What is transpiling in Angular?

• Converting TypeScript to JavaScript so browsers can execute it.

• Done using Angular CLI (ng build) with tsconfig.json settings.

 

11) What are HTTP interceptors?

• Middleware for HTTP requests and responses.
• Used for authentication, logging, and request modification.

Example:

intercept(req: HttpRequest, next: HttpHandler) {

  const clonedReq = req.clone({ setHeaders: { Authorization: 'Bearer token' } });

  return next.handle(clonedReq);

}

 

12) What is Change Detection, and how does it work?

• Updates the DOM when component data changes.

• Uses Zone.js to track changes.

• Change detection strategies

Default – Runs automatically.

OnPush – Runs only when @Input() reference changes.

Example:

@Component({ 

  selector: 'app-demo', 

  changeDetection: ChangeDetectionStrategy.OnPush

})

 

13) What is a bootstrapping module?

• The root module that initializes the Angular application.

• Declared in main.ts.

Example:

platformBrowserDynamic().bootstrapModule(AppModule);

 

Angular Scenario-Based Interview Questions

1) How do you choose an element from a component template?

You can use @ViewChild() or @ViewChildren().
Example:

@ViewChild('myDiv') divElement: ElementRef;

2) How do you deal with errors in Observables?

Use .catchError() from RxJS.
Example:

this.http.get('api/data').pipe(

  catchError(error => {

    console.error('Error occurred', error);

    return throwError(error);

  })

);

3) How to include SASS in an Angular project?

ng new my-app --style=scss

Or manually update angular.json to use SCSS.

 

4) What happens when we use the script tag within a template?

Angular removes script tags from templates for security reasons (to prevent XSS attacks).

 

5) Write a code to share Parent to Child Component data?

Use @Input().

Parent Component:

[message]="'Hello from Parent'"

 

Child Component:

@Input() message: string;

 

6) Create a TypeScript class with a constructor and a function.

typescript

class Person {

 name: string;

 constructor(name: string) {

    this.name = name;

  }

  greet() {

    return `Hello, ${this.name}`;

  }

}

Conclusion

Life gives us many opportunities. It is us who have to identify these opportunities and pace up to climb the ladder of success. Hard work never fails anyone; nothing is impossible.

Gathering essential knowledge and skills depends on the interest of the individual. Once a person garners everlasting knowledge, the path leading towards success becomes clear of many hideous obstacles.

Angular provides a great platform for every individual who is even remotely interested in the subject area. One can never have enough of anything. The more knowledge we garner, the closer we get to being perfect without skills.

With various preparations and certifications, preparing Angular interview questions can be of great benefit. The Angular interview questions give a brief idea about the situation that an individual will face with angular questions during the interview.

 

 

The Angular interview questions and answers mentioned will make the individual prepared for the interview situation overhead. Angular can provide a life-changing opportunity.

It is certainly wise to grab the chance and get prepared to face the world of temporary obstacles before enjoying the sweetness of success.

Learning new things never goes out of fashion. It always proves to be in favour of the person taking a risk.

Recommended Courses,

Data Science Master Program

Full Stack Developer Master Program

For best training and certification courses, you can reach us at Click Here or chat with our course expert. If you’re looking for ways to enhance your career, you can explore all courses offer by us and request a trial. Subscribe to our newsletters for latest infomation.