import React, { useState } from "react"; import "./styles.css"; export default function App() { const [isActive,setActive] = useState(true); return ( <div className={`container ${isActive?"green-box":"red-box"}`
To make your layout responsive, you can use media queries to change the grid structure at different screen sizes. For example: @media (max-width: 768px) { .container { grid-template-columns: repeat(2, 1fr); } } The kind of abstraction used for CSS3+ syntax provides advanced capabiliti...
import * as React from "react"; import ReactDOM from "react-dom"; export default function App() { const ref = React.useRef(); function focus() { ref.current.focus(); } return ( Focus ); } const rootElement = document.getElementById("root"); ReactDOM.render(<App />, rootEle...
Similarly, Babel converts modern JavaScript code using advanced concepts into a format older browsers can understand. While not mandatory, people frequently use Babel with React to ensure cross-browser compatibility. This may seem like a lot, but don’t worry —There are many resources to help y...
we use the special react className syntax: Example Text Of course, we also need a CSS stylesheet. This is just a regular .css file, that we need to import: importReact, { Component }from'react'// import style.css stylesheetimport'./style.css'classAppextendsComponent{constructor() {super(...
className="App-link"href="https://reactjs.org"target="_blank"rel="noopener noreferrer">Learn React);}exportdefaultApp; Copy Delete the lineimport logo from './logo.svg';. Then replace everything in thereturnstatement to return a set of empty tags:<></>. This will give you a valid p...
Since this component takes two props, we need to change a few things: importReact,{MouseEventHandler}from'react'import{buttonStyles}from'./Button.styles'typeProps={onClick:MouseEventHandler,text:string,}constButton=({onClick,text}:Props)=>({text})exportdefaultButton Let’s double-check that ...
Use the components in your appimport './App.css'; import FunctionComponent from "./components/FunctionComponent.jsx"; import {HighOrderComponent} from "./components/HighOrderComponent.jsx"; function App() { return ( <FunctionComponent/> <HighOrderComponent/> ); } export default App;Creating...
importReact,{useState}from'react';import'./App.css';functionApp(){const[submitting,setSubmitting]=useState(false);consthandleSubmit=event=>{event.preventDefault();setSubmitting(true);setTimeout(()=>{setSubmitting(false);},3000)}return(How About Them Apples{submitting&&Submtting Form...}<fields...
(TDD) approach. I’ll show you how to write both unit and functional tests, and in the process, explain what code mocks are by mocking a few libraries. I’ll be using a combination of RTL and Jest — both of which come pre-installed in any new project created with Create-React-App...