Learn React Js MCQs
Prepare React Js MCQs (Multiple choice Questions) for exam and job interviews.
How do you share state across components?
1) Using `context` or `props`
2) By using local state
3) Using `refs`
4) By creating a global variable
Answer : Option 1
What does `React.lazy` do?
1) It allows you to define a component that is loaded dynamically
2) It manages state
3) It handles side effects
4) It creates refs
Answer : Option 1
How do you create a custom hook?
1) By writing a function that uses React hooks
2) By using `useState`
3) By using `useEffect`
4) By using `useRef`
Answer : Option 1
What is the purpose of `useTransition`?
1) To mark updates as non-urgent
2) To handle state
3) To create refs
4) To manage side effects
Answer : Option 1
How do you define a functional component?
1) By creating a function that returns JSX
2) By using `class` keyword
3) By using `createRef`
4) By using `useEffect`
Answer : Option 1
What is the purpose of `useImperativeHandle`?
1) To customize the instance value that is exposed to parent components when using `ref`
2) To manage state
3) To create refs
4) To handle side effects
Answer : Option 1
How do you implement local state management?
1) Using `useState`
2) Using `useEffect`
3) Using `useRef`
4) Using `context`
Answer : Option 1
What is the purpose of `useDeferredValue`?
1) To defer the value update until the component has finished rendering
2) To manage state
3) To create refs
4) To handle side effects
Answer : Option 1
How do you perform cleanup in `useEffect`?
1) By returning a cleanup function
2) By using `useRef`
3) By using `useState`
4) By using `props`
Answer : Option 1
What is the primary benefit of using React?
1) Building user interfaces with reusable components
2) Managing backend data
3) Handling API calls
4) Optimizing server performance
Answer : Option 1