hhello_react案例 <div id="root"></div> <!-- 引入r

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <!-- 准备一个容器 -->
    <div id="root"></div>

    <!-- 引入react核心库 -->
    <script src="https://unpkg.com/react@16/umd/react.development.js"></script>
    <!-- 引入react-dom,用于支持react操作DOM -->
    <script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
    <!-- 引入babel，用于将jsx转为js -->
    <script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>

    <!-- 此处一定要写babel -->
    <script type="text/babel">
        // 创建虚拟D0M
        const VDOM = <h1>hello world</h1>
        // 渲染虚拟DOM到页面
        ReactDOM.render(VDOM, document.getElementById('root'));
    </script>
</body>

</html>