React State Management

Question 1

What is the primary purpose of state in React components?

Accepted Answer

To store and manage data that can change over time

Answer

To define the component's HTML structure

Answer

To handle CSS styling for components

Answer

To manage component imports and exports

Question 2

Which React Hook is used to add state to functional components?

Accepted Answer

useState

Answer

useEffect

Answer

useContext

Answer

useReducer

Question 3

What does the useState Hook return?

Accepted Answer

An array with the current state value and a setter function

Answer

Just the current state value

Answer

An object with state and setState properties

Answer

A function to update the state

Question 4

When should you use useReducer instead of useState?

Accepted Answer

When you have complex state logic with multiple sub-values

Answer

When you need to store simple boolean values

Answer

When working with CSS styles

Answer

When handling component mounting

Question 5

What is the correct way to update state that depends on the previous state value?

Accepted Answer

Use a function that receives the previous state as an argument

Answer

Directly modify the state variable

Answer

Use setTimeout to delay the update

Answer

Access the state variable directly in the setter

Question 6

What is prop drilling in React?

Accepted Answer

Passing props through multiple component layers to reach a deeply nested component

Answer

Creating holes in component props

Answer

Debugging props with developer tools

Answer

Optimizing prop performance

Question 7

Which React feature helps avoid prop drilling for global state?

Accepted Answer

Context API

Answer

useState Hook

Answer

Component lifecycle methods

Answer

React Router

Question 8

What is the main benefit of using a state management library like Redux?

Accepted Answer

Predictable state updates through a centralized store

Answer

Faster component rendering

Answer

Better CSS styling capabilities

Answer

Automatic API call handling

Question 9

In React's useReducer, what is the purpose of the dispatch function?

Accepted Answer

To send actions to the reducer function

Answer

To directly modify the state

Answer

To trigger component re-renders

Answer

To handle asynchronous operations

Question 10

What happens when you directly mutate state in React instead of using the setter function?

Accepted Answer

The component won't re-render because React doesn't detect the change

Answer

The application will crash immediately

Answer

The state will update faster

Answer

React will automatically fix the mutation