React Js Documentation

The Files section with a list of files like App.js, index.js, styles.css and a folder called public The code editor where you'll see the source code of your selected file The browser section where you'll see how the code you've written will be displayed The App.js file should be selected in the Files section.

React is the library for web and native user interfaces. Build user interfaces out of individual pieces called components written in JavaScript. React is designed to let you seamlessly combine components written by independent people, teams, and organizations. Join us for React Conf on Oct 7-8.

If you use a build tool or a framework, consult its documentation to learn how to add a CSS file to your project. Displaying data . JSX lets you put markup into JavaScript. Curly braces let you quotescape backquot into JavaScript so that you can embed some variable from your code and display it to the user. For example, this will display user.name

Learn how to use React, a library for building user interfaces, with Vite, a modern front-end build tool. Discover React's background, use cases, JSX syntax, and how to create a simple starter app.

The React docs at react.dev provide documentation for the latest version of React. We aim to keep the docs updated within major versions, and do not publish versions for each minor or patch version. When a new major is released, we archive the docs for the previous version as x.react.dev.

TypeScript is a popular way to add type definitions to JavaScript codebases. Learn how to integrate TypeScript into your React projects. React Developer Tools . React Developer Tools is a browser extension that can inspect React components, edit props and state, and identify performance problems. Learn how to install it here. React Compiler

The React reference documentation is broken down into functional subsections React . Programmatic React features Rules of Hooks - Hooks are defined using JavaScript functions, but they represent a special type of reusable UI logic with restrictions on where they can be called.

componentDidMount If you define the componentDidMount method, React will call it when your component is added mounted to the screen. This is a common place to start data fetching, set up subscriptions, or manipulate the DOM nodes. If you implement componentDidMount, you usually need to implement other lifecycle methods to avoid bugs.For example, if componentDidMount reads some state or

Create React App. To learn and test React, you should set up a React Environment on your computer. This tutorial uses the create-react-app.. The create-react-app tool is an officially supported way to create React applications.. Node.js is required to use create-react-app.. Open your terminal in the directory you would like to create your application.

Most pages in the React documentation contain sandboxes like this. Outside of the React documentation, there are many online sandboxes that support React for example, CodeSandbox, StackBlitz, or CodePen. To try React locally on your computer, download this HTML page. Open it in your editor and in your browser! Creating a React App