Quiz for Error Boundaries

Q1: What is the purpose of an Error Boundary in React?

A. A. To catch JavaScript errors anywhere in their child component tree B. B. To style components dynamically C. C. To manage API requests D. D. To improve rendering speed

Q2: Which lifecycle method is used to create an Error Boundary?

A. A. static getDerivedStateFromError() B. B. componentDidMount() C. C. render() D. D. shouldComponentUpdate()

Q3: Which method is called to perform side-effects after an error is caught?

A. A. componentDidCatch(error, info) B. B. componentWillUnmount() C. C. componentDidUpdate() D. D. getSnapshotBeforeUpdate()

Q4: Can Error Boundaries catch errors inside event handlers?

A. A. No, they do not catch errors in event handlers B. B. Yes, they catch all errors C. C. Only in class components D. D. Only in functional components

Q5: What is the minimum requirement to define an Error Boundary?

A. A. Define either getDerivedStateFromError or componentDidCatch B. B. Use componentDidMount C. C. Use shouldComponentUpdate D. D. Define render method only

Q6: Can functional components be Error Boundaries?

A. A. No, only class components can be Error Boundaries B. B. Yes, with hooks C. C. Only with React 18 D. D. Only with context API

Q7: What happens when an Error Boundary catches an error?

A. A. It renders a fallback UI instead of the crashed component tree B. B. It reloads the page C. C. It logs out the user D. D. It resets component state

Q8: Where should you place Error Boundaries?

A. A. Around components where errors are likely or critical B. B. At the root only C. C. Around all JSX elements D. D. Inside Redux reducers

Q9: Which of these is NOT caught by Error Boundaries?

A. A. Errors thrown inside event handlers B. B. Errors in lifecycle methods C. C. Errors during rendering D. D. Errors in constructors of child components

Q10: How can you show a custom fallback UI when an error occurs?

A. A. By rendering a fallback component in render method after error state B. B. By using setTimeout C. C. By throwing a new error D. D. By using useEffect

Q11: Can Error Boundaries recover from an error?

A. A. Yes, if the error-causing component unmounts or state changes B. B. No, error boundaries force app reload C. C. Only with Redux D. D. Only if network error

Q12: What type of errors are typically caught by Error Boundaries?

A. A. Rendering errors, lifecycle method errors, constructor errors B. B. Syntax errors C. C. Network errors D. D. CSS errors

Q13: Which React version introduced Error Boundaries?

A. A. React 16 B. B. React 15 C. C. React 17 D. D. React 18

Q14: How do you test Error Boundaries?

A. A. By causing errors in child components and checking fallback UI B. B. By simulating user clicks C. C. Using React DevTools only D. D. By Redux logging

Q15: Which method allows you to log error details?

A. A. componentDidCatch(error, info) B. B. getDerivedStateFromError C. C. render D. D. componentWillUnmount

Q16: Can multiple Error Boundaries be nested?

A. A. Yes, you can nest multiple boundaries B. B. No, only one is allowed C. C. Only with hooks D. D. Only in functional components

Q17: Which statement about Error Boundaries is true?

A. A. They do not catch errors inside themselves B. B. They catch errors globally C. C. They catch errors only in functional components D. D. They catch CSS errors

Q18: What is a fallback UI?

A. A. A UI shown when an error is caught by an Error Boundary B. B. Default page header C. C. A loading spinner D. D. The main app UI

Q19: Can Error Boundaries catch errors thrown during server-side rendering?

A. A. No, they only work on client-side rendering B. B. Yes, always C. C. Only with React 18 D. D. Only if hydration fails

Q20: Which of the following is a valid Error Boundary component?

A. A. A class component implementing static getDerivedStateFromError or componentDidCatch B. B. Any functional component C. C. A stateless component D. D. A component with hooks only