html
<!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>
<div id="root"></div>
<!-- 引入依赖 -->
<script crossorigin src="https://unpkg.com/react@18/umd/react.development.js"></script>
<script crossorigin src="https://unpkg.com/react-dom@18/umd/react-dom.development.js"></script>
<script src="https://unpkg.com/babel-standalone@6/babel.min.js"></script>
<!-- 编写React代码 -->
<script type="text/babel">
const root = ReactDOM.createRoot(document.querySelector("#root"));
//1.将文本定义成变量
let message = "Hello World"
//2.监听按钮的点击
function btnClick(){
//1.1修改数据
message = "Hello React"
// 2.重新渲染界面
rootRender()
}
//3.封装一个渲染函数
function rootRender(){
root.render((
<div>
<h2>{message}</h2>
<button onClick={btnClick}>修改文本</button>
</div>
))
}
rootRender()
</script>
</body>
</html>