React.js Challenge: 10 Multiple-Choice Questions to Assess Your Expertise.

Introduction

Top 10 M.C.Q:- Questions and Answers for improving and understanding React JS Framework. Learn and Understand React JS Framework like Pro.

1. Question: What is React.js?

A. A programming language

B. A JavaScript library for building user interfaces

C. A database management system

D. A text editor

Correct Answer: B

2. Question: What does JSX stand for in React.js?

A. JavaScript XML

B. JavaScript Extension

C. Java Syntax Extension

D. JavaScript Expression

Correct Answer: A

3. Question: In React.js, what is used to define the structure and layout of user interfaces?

A. HTML

B. CSS

C. JSX

D. Python

Correct Answer: C

4. Question: What is the virtual DOM in React.js?

A. A game engine

B. A virtual reality platform

C. An in-memory representation of the actual DOM

D. A data visualization library

Correct Answer: C

5. Question: How do you create a functional component in React.js?

A. Using the class keyword

B. Using the function keyword

C. Using the new keyword

D. Using the component keyword

Correct Answer: B

6. Question: What is the purpose of state in React.js?

A. To define the component's layout

B. To define the component's behavior

C. To store and manage data that can change over time

D. To define the component's styling

Correct Answer: C

7. Question: How do you pass data from a parent component to a child component in React.js?

A. Using the state object

B. Using the props object

C. Using the context API

D. Using the this keyword

Correct Answer: B

8. Question: What is a controlled component in React.js?

A. A component that is difficult to control

B. A component that does not accept user input

C. A component whose form elements are controlled by React's state

D. A component that uses external libraries for rendering

Correct Answer: C

9. Question: What is the purpose of the "useEffect" hook in React.js?

A. To define the component's layout

B. To handle user input

C. To perform side effects in functional components

D. To define the component's behavior

Correct Answer: C

10. Question: Which of the following is used for routing in a React.js application?

markdown
**A. Redux** 
**B. React Router** 
**C. Axios** 
**D. Webpack** 
**Correct Answer: B**