So friends, you may searching for questions and answers which are regularly asked in interviews.
Here is the Top 50 Angular Interview questions list only. You can find the answers on the internet, good resources like Geeks for Geeks or even ChatGPT. I am giving a data warehouse list of questions only.
Top 50 Angular Interview Questions You Must Know!
1. What is the main purpose of Angular?
2. What are directives in Angular and how many types of directives exist?
3. Explain data bindings and the different types.
4. What are the basic components involved in Angular?
5. What’s the difference between AngularJS and Angular?
6. What are components and modules in Angular?
7. What are decorators in Angular?
8. What is metadata or annotations in Angular?
9. What are templates in Angular?
10. What is SPA and how do you implement it in Angular?
11. Explain the importance of routing in Angular & how to implement it.
12. What is lazy loading in Angular?
13. How do you implement lazy loading in Angular?
14. What is Node.js?
15. What is NPM?
16. Why is the node_modules folder important?
17. What is package.json?
18. What is TypeScript?
19. What is the need for Angular CLI?
20. What are services in Angular?
21. When would you use content projection?
22. Explain content projection slots in Angular.
23. Why do we need ViewChild and ViewChildren in Angular?
24. What is a template reference variable?
25. Explain ContentChild and ContentChildren.
26. Differentiate between ViewChild, ViewChildren, ContentChild, and ContentChildren.
27. What is { static: true } in ViewChild?
28. What is the importance of Angular component hooks/life cycles?
29. Explain Angular life cycle hooks in detail.
30. Differentiate between constructor and ngOnInit().
31. How do you implement lazy loading in Angular?
32. How do you implement HTTP in Angular?
33. How do you pass data between components?
34. What are pipes in Angular?
35. Can you give examples of inbuilt Angular pipes?
36. How do you write a custom pipe?
37. What is RxJs and why is it needed?
38. What are observables and observers?
39. What is a stream in RxJs?
40. What is the use of subscribe in RxJs?
41. How do you unsubscribe from a stream?
42. What are operators in RxJs?
43. Where have you used RxJs in Angular?
44. Differentiate between RxJs and Promises.
45. How do you install RxJs?
46. Why is RxJs called push/reactive and not pull/imperative?
47. Name some RxJs operators.
48. What are interceptors in Angular?
49. How do you implement interceptors?
50. What are some uses of interceptors, and can we provide multi-interceptors?
Some more questions, you might find them repetitive, but I am still pasting here 😀
1. What is Angular? How does it differ from AngularJS?
2. Explain the Angular architecture and the role of components, modules, and services.
3. Describe the Angular CLI and its features.
4. What are Angular directives? Differentiate between structural and attribute directives.
5. Describe Angular modules and their significance in an Angular application.
6. What is Angular routing? How do you implement routing in an Angular application?
7. Explain Angular forms and their types.
8. What is Angular HTTP client? How do you perform HTTP requests in Angular?
9. Discuss Angular pipes and their usage.
10. Describe Angular’s built-in validators for form validation.
11. What are Angular interceptors? How do you use them?
12. Describe unit testing and end-to-end testing in Angular applications.
13. How do you communicate between components in Angular?
14. Explain the Angular component lifecycle hooks.
15. How do you create a new Angular project using the Angular CLI?
16. What is data binding in Angular? Explain the different types of data binding.
17. What is Dependency Injection (DI) in Angular? How does it work?
18. What are Angular services? How do you create and use services in Angular?
19. Explain lazy loading in Angular and its benefits.
20. How do you handle authentication and authorization in Angular applications?
21. What is the difference between promises and observables?
22. Discuss the concept of strict mode in JavaScript.
23. Explain the difference between splice() and slice() methods.
24. Describe the differences between map, filter, and reduce functions.
25. What are the template driven forms and Reactive forms?
26. What are Promises in JavaScript? How do they differ from callbacks?
27. Explain the concept of callback functions in JavaScript.
28. What is the purpose of the this keyword in JavaScript?
29. What is the difference between == and === in JavaScript?
30. What are closures in JavaScript? Provide an example.
31. Explain the differences between null and undefined.
32. What is subject and behaviour subject? Why it is used.
33. What is content projection?
34. What is EventEmitter?
35. What is change detection mechanism in Angular?
In above list, you may find some Javascript questions, but these are the questions I faced in interviews of Angular, you must prepare.
Concepts of Angular — List
Components
Templates, directives, pipes and data binding
Services and dependency Injection
Routing
Interpolation
Modules
Change detection
Below are the just some random topics you need to be prepare on.
Common Javascript Questions:
ES versions, ES5, ES6 etc.
Why TypeSript
Why JS
Promises, chain, observables, async-await
Event loop, setTimeout() => Don’t give much importance, but be prepared.
“this” operator in JS
Why callbacks are not preferred. Why move to async-await?
Coding Questions:
You must practice angular coding questions on StackBlitz, because in interview, interviewer may ask to share you the screen and give some coding task you have to complete on StackBlitz
Implement something using HTML, JS/Angular : changing of color for some div/box with some logic
Large JSON file, how you will copy that to other object (Answer: jsonify it).
Copy one object to another object.
Flat an array using JavaScript.
Shift trailing 2 elements to the start of the array.
Prepare some CSS: display flags, alignments, media queries, etc.
Angular Preparation:
Interpolation, stand-alone componenents (types of componenents), view chain, content chain
Event click, Event emitters
ngModel
Routing, Lazy Loading (syntax writing)
Testing / Test Cases using Angular
CORS
How you will debug, methods of debug in Angular.
ngTemplates: go deeper
UI Components, Services, Pipes, Directives.
CSS vs SCSS
What is Encapsulation? Change Detection.
Component lifecycle in Angular
Types of pipes (pure and impure), custom pipes.
Accessibility in Angular (Somebody try to hack you, how to prevent it)
Scenario based question:
JWT token, how to handle tokens in frontend.
What is rate limiting in frontend & backend.
HTTP response code.
Request types in REST: get, post, put, patch, delete etc.