JavaScript- 30 Important Interview Question Answer

What are the different data types in JavaScript?

What is the difference between var, let, and const?

How does JavaScript handle asynchronous code?

What is a closure, and how does it work?

What are JavaScript prototypes, and how do they work?

Explain the concept of hoisting in JavaScript.

What is the difference between == and ===?

How do you handle errors in JavaScript?

What is a promise, and how does it work?

Explain the this keyword in JavaScript.

What is event delegation?

What are higher-order functions?

What is the purpose of the bind, call, and apply methods?

How does JavaScript’s event loop work?

What are arrow functions, and how are they different from regular functions?

What is the difference between synchronous and asynchronous functions?

How do you manipulate the DOM using JavaScript?

What are template literals, and how do you use them?

What is the purpose of the fetch API?

What are modules in JavaScript, and how do you use them?

What is the difference between null and undefined?

How does JavaScript handle type coercion?

What is the role of setTimeout and setInterval?

What are JavaScript design patterns?

How do you optimize JavaScript performance?

What is the difference between Array.prototype.map and Array.prototype.forEach?

What is functional programming in JavaScript?

How do you create and use a JavaScript class?

What are JavaScript decorators, and how do they work?

How does JavaScript’s garbage collection work?