Top 50 Angular Interview Questions

ByAnkush Jain| Last Updated On Wednesday, Jun 19, 2019

Angular

Disclaimer: I am a consultant at Amazon Web Services, and this is my personal blog. The opinions expressed here are solely mine and do not reflect the views of Amazon Web Services (AWS). Any statements made should not be considered official endorsements or statements by AWS.

Please find below the top 50 most asked Angular interview questions. These questions must help you in boosting your self-confidence before you appear in the interview. These questions are applicable to all versions of Angular from Angular 2 to Angular 7.

1. What is Angular?
2. How Angular is different from AngularJS?
3. What is TypeScript?
4. Explain the lifecycle hooks of Angular.
5. What are a few building blocks of Angular?
6. What is a Component in Angular?
7. What is Directive.
8. What are the different types of Directives?
9. What is Service?
10. What are Providers in Angular?
11. In how many ways we can register providers in Angular?
12. How does DI work in Angular?
13. What is @Injectable decorator?
14. What are Configuration Decorators?
15. Name a few decorators.
16. What is Module in Angular?
17. What is feature module in Angular?
18. Use of Imports, Declarations, Providers in Angular Module?
19. Use of forRoot()?
20. How will you make the service singleton for lazy-loaded modules?
21. How does DI work in case of lazy loaded modules?
22. Difference between Component & Directive?
23. How does Angular App bootstrap itself?
24. What is Main.ts file?
25. How to bootstrap Angular App with a module other than App Module?
26. What does bootstrap module do?
27. What is BrowserModule in Angular?
28. How index.html understand component selectors?
29. How to share components between lazy-loaded modules?
30. How to pass OAuth token in Angular?
31. How to prevent few requests to not go through the interceptor?
32. How to centralized exception handling?
33. How @ViewChild can improve performance?
34. BehaviourSubject vs Observable?
35. What is ErrorHandler class in Angular?
36. JIT vs AOT?
37. Angular vs React?
38. What is Observable?
39. Promise & Observable?
40. What is RxJS?
41. Name a few RxJS operators.
42. Explain these RxJS Operators - map(), catch(), filter(), flatMap() etc.
43. What are Pipes?
44. What is a template variable in Angular?
45. What are pipes?
46. What are some inbuilt pipes & how do pass arguments in them?
47. How to create a custom pipe?
48. What are input & output properties?
49. What is Change Detection?
50. How can we improve the performance of an Angular application?