Part 9–100 Advanced JavaScript Interview Questions with Answers and Code Examples

Part 9–100 Advanced JavaScript Interview Questions with Answers and Code Examples

Welcome to the ninth part of our series on advanced JavaScript interview questions!

Introduction:

In this article, we’ll continue exploring ten more challenging questions that will test your knowledge of JavaScript concepts and techniques. Each question is accompanied by a detailed answer and code examples to help you understand the topic thoroughly. Additionally, we’ll provide external links for further reading to enhance your understanding. Let’s dive in!

81- What is the difference between “undefined” and “null” in JavaScript? Provide an example.

Answer: In JavaScript, undefined is a value that indicates the absence of a value or an uninitialized variable, while null is an assignment value that represents the intentional absence of any object value. Here's an example:

let x;
console.log(x); // Output: undefined
const y = null;
console.log(y); // Output: null

Further Reading: MDN Web Docs — undefined and MDN Web Docs — null

82- What is the purpose of the “Object.freeze()” method in JavaScript…