JavaScript is a popular programming language that is widely used in developing web applications. If you’re preparing for a JavaScript interview, you’re probably wondering what kind of questions you’ll be asked. Interviews can be stressful, but with the right preparation, you can ace them. In this article, we’ll cover the most commonly asked interview JavaScript questions to help you prepare.

Knowing these interview JavaScript questions can give you an edge over other candidates and help you land your dream job. So, let’s get started!

Core JavaScript Concepts:

1. What is JavaScript?
2. What are the data types in JavaScript?
3. What is the difference between null and undefined?
4. What is hoisting in JavaScript?
5. What is the difference between var, let, and const?
6. What are closures in JavaScript?
7. What is scope in JavaScript?
8. What is the difference between == and === in JavaScript?
9. What is the event loop in JavaScript?
10. What is the difference between synchronous and asynchronous code in JavaScript?

Object-Oriented Programming (OOP) Concepts in JavaScript:

1. What is OOP?
2. What are the pillars of OOP?
3. What is inheritance, and how does it work in JavaScript?
4. What is polymorphism?
5. What is encapsulation?
6. What is abstraction?
7. What is the difference between an object and a function in JavaScript?

JavaScript Functions:

1. What are JavaScript functions?
2. What is the difference between a function declaration and a function expression?
3. What is a higher-order function?
4. What is the call stack in JavaScript?
5. What is a callback function?

DOM and Events:

1. What is the DOM?
2. What are events in JavaScript?
3. What is event bubbling?
4. What is event capturing?
5. What is event delegation?

Promises and Async/Await:

1. What are Promises in JavaScript?
2. What is the difference between a Promise and a Callback?
3. What is Async/Await in JavaScript?
4. What is the difference between Async/Await and Promises?

jQuery:

1. What is jQuery?
2. What are the benefits of using jQuery?
3. What are the different methods in jQuery?
4. What is event chaining in jQuery?

React:

1. What is React?
2. What are the benefits of using React?
3. What is JSX in React?
4. What is the Virtual DOM in React?

Angular:

1. What is Angular?
2. What are the benefits of using Angular?
3. What is TypeScript in Angular?
4. What is Dependency Injection in Angular?