Q311. How is useMemo different from useCallback?
The following table compares both useMemo and useCallback: | Feature | `useMemo` | `useCallback` | | --- | --- | --- | | **Purpose** | Memoizes the **result of a computat...
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Q312. Does useMemo prevent re-rendering of child components?
The `useMemo` hook **does not directly prevent re-rendering of child components**. Its main purpose is to memoize the result of an expensive computation so that it doesn’...
Q313. What is `useCallback` and why is it used?
The `useCallback` is a React Hook used to memoize **function definitions** between renders. It returns the same function reference unless its dependencies change. This is...
Q314. What are Custom React Hooks, and How Can You Develop One?
**Custom Hooks** in React are JavaScript functions that allow you to **extract and reuse component logic** using React’s built-in Hooks like `useState`, `useEffect`, etc....
Q315. How does React Fiber works? Explain in detail.
React Fiber is the **core engine** that enables advanced features like **concurrent rendering**, **prioritization**, and **interruptibility** in React. Here's how it work...
Q316. What is the useId hook and when should you use it?
The `useId` hook is a React hook introduced in React 18 that generates **unique IDs** that are stable across server and client renders. It's primarily used for **accessib...
Q317. What is the useDeferredValue hook?
The `useDeferredValue` hook is used to **defer updating a part of the UI** to keep other parts responsive. It accepts a value and returns a "deferred" version of that val...
Q318. What is the useTransition hook and how does it differ from useDeferredValue?
The `useTransition` hook allows you to mark certain state updates as **non-urgent transitions**, keeping the UI responsive during expensive re-renders. It returns a `isPe...
Q319. What is the useSyncExternalStore hook?
The `useSyncExternalStore` hook is designed to **subscribe to external stores** (non-React state sources) in a way that's compatible with concurrent rendering. It's prima...
Q320. What is the useInsertionEffect hook?
The `useInsertionEffect` hook is designed for **CSS-in-JS library authors** to inject styles into the DOM before any layout effects run. It fires synchronously before DOM...