React初识 Hello React

<script crossorigin src="https://unpkg.com/react@16/umd/react.development.js"></script>
<script crossorigin src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
<script src="https://unpkg.com/babel-standalone@6/babel.min.js"></script>

<!-- 准备一个容器 -->
<div id="test"></div>

<!-- type值需要学text/babel才能写jsx语法 -->
<script type="text/babel">
//创建一个虚拟DOM
const VDOM = <h1>Hello React</h1>
//使用render函数渲染
ReactDOM.render(VDOM, document.getElementById('test'))
</script>

需要在本地服务器中运行才会有效