Angular, maintained by Google, is one of the most powerful and popular front-end frameworks. Whether you’re a fresher or have 5+ years of experience, being well-prepared with the most frequently asked Angular interview questions is key to standing out in any tech interview.
This comprehensive guide provides Angular interview questions and answers, real-world examples, and expert-level FAQs to help you succeed.
✅ Basic Angular Interview Questions
1. What is Angular?
- Angular is a TypeScript-based open-source web application framework used to develop single-page applications (SPAs).
2. What are the key features of Angular?
TypeScript support
Component-based architecture
Two-way data binding
Dependency Injection
RxJS support
Routing and navigation
3. What is a component in Angular?
- A component controls a part of the UI. It includes a class, a template (HTML), and styles.
Example:
@Component({
selector: 'app-hello',
template: `<h1>Hello Angular!</h1>`
})
export class HelloComponent {}
4. What is data binding in Angular?
Data binding allows communication between the component and the DOM. Angular supports:
Interpolation
Property binding
Event binding
Two-way binding
5. What is Angular CLI?
Angular CLI (Command Line Interface) is a tool to initialize, develop, scaffold, and maintain Angular applications easily.
Example:
ng new my-app
6. Explain modules in Angular.
An Angular module (NgModule) organizes components, directives, services, etc. Every Angular app has at least one module — the root module (AppModule).
7. What is a directive in Angular?
A directive modifies the behavior of a DOM element.
Structural Directives:
*ngIf,*ngForAttribute Directives:
ngClass,ngStyle
8. What is Dependency Injection (DI)?
- Angular uses DI to supply a component with its dependencies rather than creating them internally.
Example:
constructor(private userService: UserService) {}
9. What is a service in Angular?
- A service contains business logic and can be injected into components using DI.
10. What is routing in Angular?
- Angular uses the
RouterModuleto navigate between different components and views.
Example:
const routes: Routes = [
{ path: 'home', component: HomeComponent }
];
💼 Angular Interview Questions for 5 Years Experience
- For senior developers, Angular interviews focus more on architecture, performance, and best practices.
1. What are lifecycle hooks in Angular?
Hooks are methods invoked at different stages of a component’s lifecycle.
ngOnInit()ngOnChanges()ngOnDestroy()ngAfterViewInit()
2. What is change detection in Angular?
- Change detection is the mechanism by which Angular determines what parts of the DOM to update when data changes.
3. What is RxJS and how is it used in Angular?
- RxJS (Reactive Extensions for JavaScript) is used for handling asynchronous data using Observables.
Example:
this.http.get('api/data').subscribe(data => this.items = data);
4. How does Angular handle forms?
Angular supports:
Template-driven forms
Reactive forms
Reactive forms offer more flexibility with better testing and validation.
5. What is lazy loading in Angular?
- Lazy loading loads feature modules only when needed, improving performance.
Example:
{ path: 'admin', loadChildren: () => import('./admin/admin.module').then(m => m.AdminModule) }
6. What is a resolver in Angular routing?
- Resolvers fetch necessary data before a route is activated.
7. Explain Ahead-of-Time (AOT) compilation.
- AOT compiles Angular HTML and TypeScript into JavaScript during build time, enhancing speed and security.
8. What is a guard in Angular?
- Guards control navigation. Common ones include:
CanActivateCanDeactivateResolveCanLoad
9. How do you optimize Angular applications?
Lazy loading
OnPush change detection
TrackBy function in *ngFor
Tree-shaking and AOT compilation
10. What is the difference between Observable and Promise?
| Feature | Observable | Promise |
|---|---|---|
| Multiple values | Yes | No |
| Lazy execution | Yes | Yes |
| Cancelable | Yes | No |
🔟 Real-World Angular Examples
Custom Pipe to capitalize words
Reactive form with validation
HTTP GET request using HttpClient
Building a dynamic table with
*ngForImplementing lazy loading routes
Creating a directive to change text color
Navigation using
RouterLinkUsing guards for authentication
Display data using
ngIfandngSwitchImplementing services for shared state management
🙋♀️ Frequently Asked Questions (FAQs)
Q1. What is the difference between AngularJS and Angular?
- AngularJS (v1.x) uses JavaScript and is based on MVC. Angular (v2+) uses TypeScript and is component-based with modern architecture.
Q2. Why use Angular for web development?
- Angular offers structured architecture, two-way data binding, TypeScript support, and powerful CLI tools that improve development efficiency.
Q3. What tools do experienced Angular developers use?
Angular CLI
RxJS
NGX Bootstrap
ESLint
Jasmine & Karma for testing
Prettier for formatting
Q4. How can I prepare for Angular interviews?
Master core concepts (components, services, routing)
Build small projects
Practice with real coding problems
Stay updated with the latest Angular versionsk
Q5. Which version of Angular is used in most interviews?
- Usually the latest LTS (Long-Term Support) version or Angular 13+. Always ask the recruiter which version they use.
📌 Conclusion
- Whether you’re a fresher or a seasoned Angular developer with 5 years of experience, mastering these Angular interview questions and answers will significantly improve your chances in technical interviews. Pair these concepts with practical coding and stay updated on Angular best practices to become a top-tier candidate.
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