Build UIs from Reusable React Components
React composes web and native interfaces from JavaScript functions using JSX markup, hooks for state like useState, and scales via frameworks like Next.js without mandating full rewrites.
Composable Components Using JS and JSX
React structures UIs as hierarchies of reusable components defined as JavaScript functions. Pass props down to child components like Thumbnail, LikeButton, and Video, which handle specific rendering logic. For lists, use array methods like map() with keys for efficient updates: videos.map(video => <Video key={video.id} video={video} />). Conditional logic stays in JS: compute headings like ${count} ${count > 1 ? 'Videos' : 'Video'} before rendering. JSX embeds markup directly in functions, keeping logic and output co-located for easier maintenance than separate templates.
This approach works solo or in teams since components from any source integrate seamlessly without a rigid global structure.
State-Driven Interactivity with Hooks
Components re-render on prop changes, but for user input, use hooks like useState to manage local state: const [searchText, setSearchText] = useState('');. Filter data reactively—filterVideos(videos, searchText)—and pass updated props to children like SearchInput with onChange={newText => setSearchText(newText)}. React handles DOM diffs and updates efficiently.
Adopt incrementally: embed interactive components into existing HTML pages without a full SPA rewrite.
Full-Stack Apps and Cross-Platform Rendering
Pair React with frameworks like Next.js or React Router for routing and data fetching. Server components fetch async data—await db.Confs.find({ slug })—and stream HTML with Suspense boundaries: <Suspense fallback={<TalksLoading />}><Talks confId={conf.id} /></Suspense>. This enables progressive loading before JS hydrates.
For native, React Native and Expo render platform views directly (no webviews), sharing component skills across web, iOS, Android. Web uses standard APIs for responsiveness; native leverages OS strengths for authentic feel.
React prioritizes stability: changes test on billions of user sessions via Meta's 100k+ components, with gradual upgrades.
Ecosystem and Community Resources
Two million monthly doc visitors form a global community of developers, designers, and researchers. Explore history via talks like React Conf 2021 videos (19 total, covering React 18, Suspense, accessibility). Latest news includes security fixes and React Foundation under Linux Foundation.