The most popular UI library. Build component trees, manage state, and create fast, interactive UIs.
React is a JavaScript library for building user interfaces.
Core concepts:
- JSX — HTML-like syntax in JS
- Components: functional components (hooks era)
- Props, state, lifting state up
- useEffect, useState, useRef, useCallback, useMemo, useContext
- Component lifecycle via hooks
- Controlled vs uncontrolled components
- React Router v6 — SPA routing
- Context API for lightweight state sharing
- React Query / TanStack Query — server state management
- Zustand or Redux Toolkit — client state management
Performance:
- React.memo, useMemo, useCallback
- Code splitting with React.lazy & Suspense
- Virtualization for long lists (react-window)
Ecosystem:
- Next.js — React framework with SSR/SSG
- Vite — fast dev server and bundler
Core concepts:
- JSX — HTML-like syntax in JS
- Components: functional components (hooks era)
- Props, state, lifting state up
- useEffect, useState, useRef, useCallback, useMemo, useContext
- Component lifecycle via hooks
- Controlled vs uncontrolled components
- React Router v6 — SPA routing
- Context API for lightweight state sharing
- React Query / TanStack Query — server state management
- Zustand or Redux Toolkit — client state management
Performance:
- React.memo, useMemo, useCallback
- Code splitting with React.lazy & Suspense
- Virtualization for long lists (react-window)
Ecosystem:
- Next.js — React framework with SSR/SSG
- Vite — fast dev server and bundler