Quiz for Component Lifecycle (Class-based)

Q1: Which lifecycle method is invoked immediately after a component is mounted?

A. componentDidUpdate() B. componentWillMount() C. componentDidMount() D. componentWillUnmount()

Q2: What is the primary purpose of componentDidMount()?

A. Update state B. Access DOM nodes or perform API calls C. Render JSX D. Clean up listeners

Q3: Which lifecycle method is called just before a component is removed from the DOM?

A. componentWillUnmount() B. componentDidUnmount() C. componentDidRemove() D. componentWillRemove()

Q4: Which method is triggered after every update?

A. componentDidMount() B. componentWillMount() C. componentDidUpdate() D. render()

Q5: What are the parameters of componentDidUpdate?

A. prevProps, prevState B. currentProps, currentState C. newProps, newState D. props, state

Q6: Which lifecycle method is unsafe and deprecated in newer React versions?

A. componentDidMount() B. componentWillReceiveProps() C. render() D. componentDidUpdate()

Q7: What does componentWillUnmount typically handle?

A. Initialization B. Rendering JSX C. Memory cleanup like removing event listeners D. Updating props

Q8: Which method is invoked before render when new props or state are being received?

A. getSnapshotBeforeUpdate() B. componentDidMount() C. shouldComponentUpdate() D. componentWillUnmount()

Q9: Which method can return a value to be used in componentDidUpdate?

A. getSnapshotBeforeUpdate() B. componentWillUpdate() C. render() D. componentWillMount()

Q10: Which lifecycle method is guaranteed to run only once?

A. componentDidUpdate() B. render() C. componentWillReceiveProps() D. componentDidMount()

Q11: Which method determines if the component should re-render?

A. render() B. componentWillMount() C. shouldComponentUpdate() D. componentDidUpdate()

Q12: What is returned from getSnapshotBeforeUpdate()?

A. Boolean B. DOM Node C. Any value to pass to componentDidUpdate() D. JSX Element

Q13: Which of these lifecycle methods is best for making network requests?

A. componentDidMount() B. shouldComponentUpdate() C. componentWillReceiveProps() D. getSnapshotBeforeUpdate()

Q14: Which method is used to clean up resources?

A. componentDidMount() B. componentDidUpdate() C. componentWillUnmount() D. componentWillReceiveProps()

Q15: Where should initial AJAX calls be made in a class component?

A. render() B. componentWillMount() C. componentDidMount() D. shouldComponentUpdate()

Q16: In which method can you access previous props and state?

A. componentWillMount() B. getSnapshotBeforeUpdate() C. componentDidUpdate() D. render()

Q17: Which method is NOT a real lifecycle method?

A. componentWillUnmount() B. componentWillReceiveProps() C. componentWillDelete() D. componentDidUpdate()

Q18: What is the correct order of lifecycle methods on mount?

A. constructor → render → componentDidMount B. render → constructor → componentDidMount C. componentDidMount → render → constructor D. constructor → componentDidMount → render

Q19: Which method is used to prepare the component before it mounts?

A. componentDidMount() B. constructor() C. componentWillMount() D. componentDidUpdate()

Q20: Which lifecycle method is called if shouldComponentUpdate returns false?

A. render() B. componentDidUpdate() C. componentWillUnmount() D. None of the above