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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.
Current version of React.JS is V18.0.0 (April 2022). Initial Release to the Public (V0.3.0) was in July 2013. React.JS was first used in 2011 for Facebook's Newsfeed feature. Facebook Software Engineer, Jordan Walke, created it. Current version of create-react-app is v5.0.1 (April 2022).
When creating a React component, the component's name MUST start with an upper case letter. Class Component. A class component must include the extends React.Component statement. This statement creates an inheritance to React.Component, and gives your component access to React.Component's functions.
Get started for free . Start by including three scripts, the first two let us write React code in our JavaScripts, and the third, Babel, allows us to write JSX syntax and ES6 in older browsers. You will learn more about JSX in the React JSX chapter.
Create React Application. Facebook has created a Create React Application with everything you need to build a React app. It is a a development server that uses Webpack to compile React, JSX, and ES6, auto-prefix CSS files. The Create React App uses ESLint to test and warn about mistakes in the code.
Handling forms is about how you handle the data when it changes value or gets submitted. In HTML, form data is usually handled by the DOM. In React, form data is usually handled by the components. When the data is handled by the components, all the data is stored in the component state. You can control changes by adding event handlers in the ...
To add React Router in your application, run this in the terminal from the root directory of the application: npm i -D react-router-dom. Note: This tutorial uses React Router v6. If you are upgrading from v5, you will need to use the @latest flag: npm i -D react-router-dom@latest.
import { useState, createContext, useContext } from "react"; Then you can access the user Context in all components: function Component5() { const user = useContext(UserContext); return ( <> <h1>Component 5</h1> <h2>{`Hello ${user} again!`}</h2> </> ); }
We can embed JavaScript expressions in JSX by using curly braces: function Garage(props) { const cars = props.cars; return ( <> <h1>Garage</h1> {cars.length > 0 && <h2>. You have {cars.length} cars in your garage. </h2> } </> ); } const cars = ['Ford', 'BMW', 'Audi']; const root = ReactDOM.createRoot(document.getElementById('root'));
Hooks were added to React in version 16.8. Hooks allow function components to have access to state and other React features. Because of this, class components are generally no longer needed. Although Hooks generally replace class components, there are no plans to remove classes from React.
