Top 50 JavaScript Interview Questions Answer

JavaScript

Here we provide the list of top 50 JavaScript interview questions answer.

  1. What is JavaScript ?
  2. How many data types in JavaScript ?
  3. What is difference between var, let & const ?
  4. What is Object.seal and Object.freeze ?
  5. What is prototype in JavaScript ?
  6. How to implement inheritance in JavaScript ?
  7. What is closure ?
  8. What is function declaration and function expression in JavaScript ?
  9. Difference between sessionStorage & localStorage in JavaScript ?
  10. What is Objet.keys, Object.values and Object.entries in JavaScript ?
  11. What is object.assign in JavaScript ?
  12. Array methods in JavaScript.
  13. What is difference between deep copy & shallow copy ?
  14. What is event bubbling and event capturing in JavaScript ?
  15. What is callback and callback hell ?
  16. What is promise in JavaScript?
  17. What is async/await in JavaScript ?
  18. What is the new feature of ES6 ?
  19. What is IIFE ?
  20. What is difference arrow function & normal function in JavaScript ?
  21. What is difference between function declaration & function expression ?
  22. How to implement bubble sort ?
  23. What is difference between slice & splice ?
  24. What is Nan ?
  25. What is difference between == & === ?
  26. What is spread operator ?
  27. what is rest operator ?
  28. What is arguments in JavaScript ?
  29. What is difference between map, filter & reduce ?
  30. What is difference between type error & reference error in JavaScript ?
  31. How to remove duplicate elements from an array ?
  32. How to prevent modify an object property ?
  33. What is template literal ?
  34. What is hoisting in JavaScript ?
  35. What is pure function in JavaScript ?
  36. What is curry function ?
  37. What is SPA ?
  38. What is event delegation & event propagation ?
  39. What is design pattern in JavaScript ?
  40. What is event loop in JavaScript ?
  41. What is truthy & falsy in JavaScript ?
  42. How many way to empty an array in JavaScript ?
  43. Make palindrome using predefined function in JavaScript.
  44. What is difference between null & undefined ?
  45. What is difference between call, bind & apply ?
  46. How to get length of an object ?
  47. What isArray() in JavaScript ?
  48. How to get 2nd largest element from an array ?
  49. How to compare two objects in JavaScript ?
  50. How to compare two array in JavaScript ?

If you have prepared above these questions then you can sure crack the JavaScript interview.

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