React
由Facebook开源的用于动态构建用户界面的 JavaScript 库(只关注于视图)。
特点
声明式编码
组件化编码
React Native 编写原生应用
高效
使用虚拟DOM,不总直接操作真实DOM
DOM Diffing算法,最小页面重绘
安装React
react.js
:React核心库。react-dom.js
:提供操作DOM的react扩展库。babel.min.js
:解析JSX语法代码转为JS代码的库。
Hello World
非JSX方式
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport"
content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<div id="app"></div>
<script src="https://unpkg.com/react@17/umd/react.development.js" crossorigin></script>
<script src="https://unpkg.com/react-dom@17/umd/react-dom.development.js" crossorigin></script>
<script type="text/javascript">
// 创建虚拟dom
const vdom = React.createElement("h1", {id: "title"}, "Hello World");
// 渲染虚拟dom到页面指定的div中
ReactDOM.render(vdom, document.getElementById('app'));
</script>
</body>
</html>
JSX方式
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport"
content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
</head>
<body>
<div id="app"></div>
<script src="https://unpkg.com/react@17/umd/react.development.js" crossorigin></script>
<script src="https://unpkg.com/react-dom@17/umd/react-dom.development.js" crossorigin></script>
<script src="https://unpkg.com/babel-standalone@6/babel.min.js"></script>
<script type="text/babel">
// 创建虚拟dom
const vdom = (
<h1 id="title">Hello World</h1>
);
// 渲染虚拟dom到页面指定的div中
ReactDOM.render(vdom, document.getElementById('app'));
</script>
</body>
</html>
最后更新于
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