Learn React - 10 Code Examples & CST Typing Practice Test
React is a declarative, component-based JavaScript library for building user interfaces, primarily for single-page applications. It allows developers to create reusable UI components and manage application state efficiently.
Learn REACT with Real Code Examples
Updated Nov 21, 2025
Installation Setup
Install Node.js and npm/yarn
Create project using Create React App or Vite
Install React and ReactDOM via npm
Use JSX syntax in `.js` or `.jsx` files
Run project using development server (npm start)
Environment Setup
Install Node.js and npm
VS Code or preferred IDE
Browser for testing
React DevTools extension
Optional: TypeScript setup
Config Files
package.json - project dependencies
webpack.config.js - bundler config
.babelrc - transpiler config
tsconfig.json - for TypeScript React
public/index.html - main HTML template
Cli Commands
npx create-react-app my-app - initialize project
npm start - run development server
npm run build - create production build
npm test - run tests
npm install package - add dependencies
Internationalization
React-Intl or i18next libraries
Dynamic language switching
RTL and LTR support
Locale-based formatting for dates/numbers
Translation JSON files or APIs
Accessibility
Use semantic HTML
Focus management and keyboard navigation
ARIA attributes for dynamic components
Screen reader support
Avoid visual-only cues
Ui Styling
CSS Modules or Styled Components
Inline styles or CSS-in-JS
Theming via context or libraries
Responsive layouts with CSS/JSX
Animations with React Transition Group or Framer Motion
State Management
Local state with useState
Side effects with useEffect
Global state with Context API
Advanced state with Redux/MobX
Persist state with localStorage/sessionStorage
Data Management
Use props for data passing
Fetch APIs with fetch/axios
Use useReducer for complex state
Cache data to optimize performance
Use Context/Redux for app-wide state
Frequently Asked Questions about React
What is React?
React is a declarative, component-based JavaScript library for building user interfaces, primarily for single-page applications. It allows developers to create reusable UI components and manage application state efficiently.
What are the primary use cases for React?
Single-page web applications (SPAs). Dynamic user interfaces for web apps. Mobile apps via React Native. Reusable component libraries. Interactive dashboards and admin panels
What are the strengths of React?
Reusable and maintainable components. High performance with virtual DOM. Large community and ecosystem. Rich tooling and developer support. Supports both web and mobile (React Native)
What are the limitations of React?
Requires build tools (Webpack, Babel) for JSX. Learning curve for hooks and state management. Not a full framework (needs routing, state libraries). Frequent updates may require learning new APIs. SEO optimization requires server-side rendering or frameworks like Next.js
How can I practice React typing speed?
CodeSpeedTest offers 10+ real React code examples for typing practice. You can measure your WPM, track accuracy, and improve your coding speed with guided exercises.