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30+ JavaScript Interview Questions


JavaScript Interview Questions:

  1. What is Ecmascript in Javascript
  2. What is difference between let ,cons and var
  3. What is spread operator, Rest operator, default parameter
  4. What is deep copy and shallow copy in Javascript
  5. What is promise , callback function , async await in Javascript
  6. What is difference between promise and callback in Javascript
  7. What is event bubbling and event capturing in Javascript
  8. What is higher order function in Javascript
  9. Explain different-2 types of function in Javascript
  10. What is arrow function in Javascript
  11. Why we use call, apply bind method in Javascript
  12. How many way to create object in Javascript
  13. What is prototype inheritance in Javascript
  14. What is typescript
  15. What are the array method , string method
  16. What is difference between java and javascript
  17. What is throttling and debouncing in js
  18. What is Null and undefined in javascript
  19. What are the falsy values in javascript
  20. What is execution context, event loop ,stack, call queue,microtask queue in Javascript
  21. What is setTimeOut and setInterval in Javascript
  22. What is object.seal and object.freeze in Javascript
  23. What is difference between map and set in Javascript
  24. What is Weakmap and Weakset in Javascript
  25. What is sessionStorage, localStorage , cookie in javascript
  26. Write a program to sort an array
  27. What is use of json.stringify and json parse() method in Javascript
  28. What are is map, filter , reducer in javascript
  29. What is generator function in Javascript
  30. How to stop event propagation in Javascript
  31. What is closure in Javascript
  32. What is housing in Javascript
  33. What is dead zone in Javascript
  34. What is function currying in Javascript
  35. What is mutation observer in Javascript
  36. What is memorization in javascript