Top 51 Angular Interview Questions And Answers 2024

1. What is Angular? Why was it introduced?

2. What is TypeScript?

3. What is data binding? Which type of data binding does Angular deploy?

4. What are Single Page Applications (SPA)?

5. Differentiate between Angular and AngularJS

6. What are decorators in Angular? 

7. Mention some advantages of Angular.

8. What are the new updates with Angular10? 

9. What are Templates in Angular?

10. What are Annotations in Angular?

11. What are Directives in Angular?

12. What is an AOT compilation? What are its advantages?

13. What are Components in Angular?

14. What are Pipes in Angular? 

15. What is the PipeTransform interface?

16. What are Pure Pipes? 

17. What are Impure Pipes?

18. What is an ngModule?

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

20. What is view encapsulation in Angular?

21. What are controllers?

22. What do you understand by scope in Angular?

23. Explain the lifecycle hooks in Angular

24. What is String Interpolation in Angular?

25. What are Template statements?

26. What is the difference between AOT and JIT? 

27. Explain the @Component Decorator.

28. What are Services in Angular? 

29. What are Promises and Observables in Angular? 

30. What is ngOnInit? How is it defined? 

31. How to use ngFor in a tag? 

32. What are Template and Reactive forms?

33. What is Bootstrap? How is it embedded into Angular? 

34. What is Eager and Lazy loading? 

35. What type of DOM does Angular implement? 

36. Why were client-side frameworks like Angular introduced?

37. How does an Angular application work?

38. Explain components, modules and services in Angular.

39. How are Angular expressions different from JavaScript expressions?

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

41. How do you share data between components in Angular?

42. Explain the concept of dependency injection.

43. Explain MVVM architecture.

44. What are RxJs in Angular?

45. What exactly is a parameterized pipe?

46. What are class decorators?

47. What are Method decorators?

48. What are property decorators?

49. What are router links?

50. What exactly is the router state?

51. What does Angular Material mean?

Angular Interview Questions And Answers

1. What is Angular? Why was it introduced?

Ans. Angular is a TypeScript-based open-source front-end web application framework developed by Google. It is designed to make both the development and testing of such applications easier. The framework provides a comprehensive set of tools and libraries for building client-side applications.

2. What is TypeScript?

Ans. TypeScript is a superset of JavaScript that adds static typing to the language.It is developed and maintained by Microsoft.TypeScript code is transpiled into JavaScript code, which can then be executed in any JavaScript environment.

3.What is data binding? Which type of data binding does Angular deploy?

Ans.Data binding is a mechanism to synchronize the state of a component with the DOM.Angular supports two-way data binding, where changes in the model (component) automatically update the view (DOM) and vice versa.

4.What are Single Page Applications (SPA)?

Ans.SPAs are web applications that load a single HTML page and dynamically update the content as the user interacts with the app.They provide a more fluid and responsive user experience by avoiding full page reloads

5.Differentiate between Angular and AngularJS

Ans.Angular is the newer version (often referred to as “Angular 2+” or just “Angular”) and is a complete rewrite of AngularJS.Angular is written in TypeScript, whereas AngularJS is written in JavaScript.Angular uses a component-based architecture, while AngularJS uses a directive-based architecture.Angular has better performance, improved dependency injection, and enhanced tooling compared to AngularJS.

6.What are decorators in Angular? 

Ans.Decorators are a design pattern in Angular used to attach metadata to classes or their members (properties, methods).They are prefixed with the @ symbol and are used to configure the behavior of classes or members.Common decorators in Angular include @Component, @Injectable, and @NgModule.

7.Mention some advantages of Angular.

Ans.Modularity: Angular uses a modular approach with components, making it easier to organize and scale code.Two-Way Data Binding: Simplifies the synchronization of the model and the view.Dependency Injection: Promotes maintainability and testability by allowing components to be loosely coupled.Cross-Platform Development: Angular facilitates the development of web, mobile, and desktop applications.

8. What are the new updates with Angular10? 

Ans.Angular 10 brings significant enhancements and changes to the development framework. Notably, the upgrade to TypeScript 3.9 indicates a move away from supporting older TypeScript versions. The framework now enforces stricter development practices, with increased error-level logging for unknown property bindings or element names in templates. Developers can opt for a more rigorous project setup using the optional strict setting introduced with the ng new command. NGCC features, including a program-based entry point finder, have been integrated. The update also includes improvements to URL routing, deprecation of certain APIs, bug fixes addressing issues like compiler behavior and migration errors, and an upgraded default browser configuration for new projects. These updates collectively reflect Angular 10’s commitment to refining developer tools, code quality, and application performance. Staying informed through the official Angular documentation is recommended for developers to leverage these advancements effectively.

9.What are Templates in Angular?

Ans. Templates in Angular are used to define the view of an Angular component.They are written in HTML with Angular-specific syntax to incorporate dynamic data and binding expressions.Templates define how the user interface should be rendered based on the component’s state.

10. What are Annotations in Angular?

Ans.In Angular, annotations are used through decorators to add metadata to classes.Annotations help Angular understand how to process and use a class.Examples include @Component for defining a component, @Injectable for services, and @NgModule for defining modules.