Question Bank
721 approved questions from the community
What is the difference between Shadow DOM and Virtual DOM?
What is the main difference between createElement and cloneElement?
What is the purpose of getSnapshotBeforeUpdate lifecycle method?
What is the diffing algorithm in React?
What is render hijacking in React?
What is the purpose of useSyncExternalStore?
What is the purpose of flushSync in React 18?
What is the main difference between React Router's Page Router and App Router in Next.js?
What happens if you return a Promise from useEffect?
What is the main purpose of React Fiber's reconciliation algorithm?
When using React.lazy() for code splitting, what component must wrap the lazy-loaded component?
Custom hooks must follow the same rules as built-in hooks, including starting with 'use' prefix.
What problem does React Concurrent Mode primarily solve?
What is the purpose of getDerivedStateFromProps lifecycle method?
useDeferredValue can help keep the UI responsive during expensive re-renders.
What is the main difference between useTransition and useDeferredValue?
React can combine multiple useReducer hooks with Context to create a scalable state management solution.
useLayoutEffect can cause layout thrashing if used improperly.
Which of the following are valid ways to optimize React performance? (Select all that apply)
Which statements about Error Boundaries are correct? (Select all that apply)