JavaScript Interview Questions
Master JavaScript with our comprehensive collection of 52 interview questions covering everything from basics to advanced concepts.
52 Questions
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Answers
Basic Questions
13 Questions1
What is JavaScript, and what are its main uses?
2
Explain the difference between var, let, and const.
3
What are the data types in JavaScript?
4
What is hoisting in JavaScript?
5
Explain the concept of closures.
6
What is the difference between == and ===?
7
What are arrow functions?
8
What is the 'this' keyword in JavaScript?
9
Explain the concept of prototypes in JavaScript?
10
Explain the concept of scope in JavaScript?
11
What are objects in javascript, how do you create them?
12
What are functions in javascript, how do you create them?
13
How do you work with arrays in Javascript?
Intermediate Questions
14 Questions21
What is the event loop in JavaScript?
22
What are Promises in JavaScript?
23
What is async/await?
24
What is the difference between call, apply, and bind?
25
Error Handling in JavaScript?
26
What is synchronous and asynchronous code in JS?
27
What is destructuring in JavaScript?
28
let and const Block Scope in JavaScript?
29
What is the spread operator?
30
What are modules in JavaScript?
31
How to handle DOM manipulation in JavaScript?
32
What is concept of Event delegation in JS?
33
What is the different ways to store data in browser?
34
How do you use classes in Javascript?
Advanced Questions
16 Questions41
Explain the concept of Currying and partial application in JS?
42
What are prototypes and prototypal inheritance?
43
What is event delegation?
44
What are generators in JavaScript?
45
What are proxies and reflect?
46
What is memoization?
47
What are Web Workers?
48
What are Service Workers?
49
Explain pattern matching in JavaScript?
50
Explain the concept of decorators in JavaScript?
51
Explain new SET methods like union, intersection, difference?
52
How does array grouping work in JavaScript?
53
Explain async context propagation in JavaScript?
54
What is web workers and how do they work?
55
Explain service workers and their use cases?
56
Explain the concept of functional programming in JavaScript?
ES6+ Features
5 QuestionsPerformance & Best Practices
4 QuestionsReady to Test Your JavaScript Knowledge?
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