Popular React Interview Questions and Answers
- What is React and Why is it Needed?
- Virtual DOM in React
- React Fiber and Virtual DOM Update Process
- Why is key Needed in React?
- What is Batching in React?
- What is JSX in React?
- How useState Works in React?
- How useEffect Works in React?
- How useLayoutEffect Works in React and How Does it Differ from useEffect?
- How useRef Works in React?
- useImperativeHandle Hook
- How useCallback Works and Why is it Needed
- How useMemo Works and Why is it Needed
- What is React.memo and Why is it Needed
- What is useReducer in React?
- React.lazy and Suspense — Lazy Components in React
- What is Context and useContext Hook in React
- Rules for Using Hooks in React
- Custom Hooks
- Controlled and Uncontrolled Components in React
- Component Rendering Order and Hook Calling in React
- Reasons for Component Re-rendering in React
- What is Virtualization and Why is it Needed
- What is HOC and Why is it Needed
- What is React.PureComponent
- What is React.Portal
- What is React.Fragment
- What is React.Children
- Difference Between Functional and Class Components in React
- Component Lifecycle Methods in React
- What is Prop Drilling and How to Avoid it
- Error Boundaries in React
- Reconciliation in React
- Synthetic Events in React
- React.StrictMode
- Refs in React (useRef, createRef, forwardRef)