JavaScript Interview Questions Pdf - 1

Question: 1

What is event delegation in JavaScript?

Event delegation is a technique where a single event listener is attached to a parent element to listen for events that occur on its children. This is particularly useful when dealing with dynamically added elements.

Question: 2

What is the 'this' keyword in JavaScript?

The 'this' keyword refers to the object on which a method is being invoked or the context in which a function is called.

Question: 3

What are JavaScript modules and how do they improve code organization?

JavaScript modules are reusable pieces of code that encapsulate related functionality and are designed to promote modularity, encapsulation, and code reuse, leading to better code organization and maintainability.

Question: 4

Explain hoisting in JavaScript?

Hoisting is JavaScript's default behavior of moving variable and function declarations to the top of their containing scope during compilation.

Question: 5

What is the difference between synchronous and asynchronous JavaScript?

Synchronous JavaScript executes code sequentially, blocking further execution until the current operation is completed, whereas synchronous JavaScript allows multiple operations to be executed concurrently, without blocking the main execution thread.