Quiz for useState

Q1: What does the useState hook allow you to do in React?

A. Create new components B. Manage state in functional components C. Perform side effects D. Navigate between routes

Q2: What is the correct syntax to initialize state using useState?

A. const [state, setState] = useState() B. useState = [state, setState]() C. const state = useState() D. state, setState = useState()

Q3: What type of argument can you pass into useState?

A. Only strings B. Only numbers C. Any type D. Only arrays

Q4: What happens when you call the state updater function?

A. Nothing B. Component rerenders C. Component unmounts D. Component reloads

Q5: Which import is required to use useState?

A. import { useState } from "react" B. import React.useState from "react" C. import useState from "react-dom" D. useState is globally available

Q6: How many values does useState return?

A. 1 B. 2 C. 3 D. 4

Q7: Can you use multiple useState calls in a single component?

A. No B. Yes C. Only one per component D. Only in class components

Q8: What is the default value of state if not set?

A. null B. undefined C. "" (empty string) D. 0

Q9: What will happen if you update state with the same value?

A. Component rerenders B. Component throws error C. Nothing happens D. Component unmounts

Q10: What kind of function can be passed to useState?

A. Async only B. Callback only C. Lazy initializer function D. Promise only

Q11: What is the main benefit of using useState in React?

A. Improves styling B. Manages lifecycle C. Enables state in functional components D. Improves SEO

Q12: What does the second element returned from useState do?

A. Initializes component B. Resets DOM C. Updates state D. Validates form

Q13: How can you set state based on the previous value?

A. UseEffect B. Pass a function to setState C. Use useCallback D. Use setTimeout

Q14: Where should useState be called?

A. Inside loops B. Inside event handlers C. At the top level of a component D. Inside conditions

Q15: Which hook would you use instead of this.setState in class components?

A. useEffect B. useContext C. useState D. useRef

Q16: Is state updated synchronously with useState?

A. Yes B. No C. Only in strict mode D. Depends on React version

Q17: What happens if you call useState inside a loop?

A. State works normally B. Hook order will be inconsistent C. Component runs faster D. Nothing changes

Q18: What does useState return when called?

A. An object B. An array C. A string D. A number

Q19: Can setState in useState accept a callback like in class components?

A. Yes B. No C. Only in production mode D. Only in class components

Q20: What’s the best practice for naming the setter function in useState?

A. Use any name B. Use uppercase only C. Use camelCase starting with "set" D. Name doesn’t matter