mcq reactjs vol1

 MCQ on REACTJS Vol1

1.

What is the primary reason for using the 'Virtual DOM' in React?

2.

Which React hook is intended to handle side effects such as data fetching or subscriptions?

3.

In React, what is the 'key' prop used for when rendering lists?

4.

What is 'JSX' in the context of React development?

5.

How can you pass data from a parent component down to a child component?

6.

What does the 'useCallback' hook return?

7.

What is the correct way to update state in a functional component using 'useState'?

8.

What is the purpose of 'React.Fragment'?

9.

Which hook provides an alternative to 'useState' for complex state logic?

10.

What happens if you omit the dependency array in 'useEffect'?

11.

What is 'Prop Drilling'?

12.

What is the purpose of 'useRef'?

13.

Which of these is a Rule of Hooks?

14.

What does 'React.memo' do?

15.

How do you handle a click event in a React component?

16.

What is the 'Context API' primarily used for?

17.

Which method is used to create a context object?

18.

What does it mean for a component to be 'Controlled' in React forms?

19.

What is the purpose of 'useLayoutEffect'?

20.

In React, what does 'Lifting State Up' refer to?

Ans

1. A

2. B

3. A

4.A

5.B

6.A

7.C

8.C

9.B

10.D

11.B

12.B

13.B

14.C

15.C

16.B

17.B

18.B

19.B

20.A