Top 30 JavaScript Interview Questions and Answers for 2024

Top 30 JavaScript Interview Questions and Answers for 2024

 

https://javascriptcentric.medium.com/top-30-javascript-interview-questions-and-answers-for-2024-7f1e2d1d0638

Top 30 JavaScript Interview Questions and Answers for 2024

 

Level-1: Basic

1. Is Javascript single-threaded?

2. Explain the main component of the JavaScript Engine and how it works.

3. Explain the event loop in JavaScript and how it helps in asynchronous programming.

4. Difference between var, let, and const ?

5. Different data types in Javascript?

6. What is callback function and callback hell ?

7. What is Promise and Promise chaining?

8. What is async/await ?

9.What is the difference between == and === operators ?

10. Different ways to create an Object in Javascript ?

11. What is rest and spread operator?

12. What is a higher-order function?

Level-2 : Intermediate

13. What is Closure? What are the use cases of Closures?

14. Explain the concept of hoisting in JavaScript.

15. What is a Temporal dead zone?

16. What is a prototype chain? and Object.create() method?

17. What is the difference between Call, Apply, and Bind methods?

18. What are lambda or arrow functions?

19. What is the currying function?

20. What are the features of ES6?

Level-3: Expert

21. What is Execution context, execution stack, variable object, scope chain?

22. What is the priority of execution of callback, promise, setTimeout, process.nextTick()?

23. What is the Factory function and generator function?

24. Different ways to clone (Shallow and deep copy of object) an object?

25. How to make an object immutable? (seal and freeze methods)?

26. What is Event and event flow, event bubbling and event capturing?

27. What is Event delegation?

28. What are server-sent events?

29. What is a web worker or service worker in javascript?

30. How to compare 2 JSON objects in javascript?