reactjs - 为什么我的反应代码适用于 jsfiddle 但不适用于本地服务器
问题描述
此代码适用于 jsfiddle
https://jsfiddle.net/2gkzqw0o/2/
而我在本地服务器上得到一个空白屏幕，为什么？
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<meta http-equiv="x-ua-compatible" content="ie=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
?
<title>test</title>
<link rel="stylesheet" href="css/main.css" />
<link rel="icon" href="images/favicon.png" />
<script crossorigin src="https://unpkg.com/react@17/umd/react.development.js"></script>
<script crossorigin src="https://unpkg.com/react-dom@17/umd/react-dom.development.js"></script>
<script src="app.js"></script>
</head>
<body>
<div id="app"></div>
</body>
</html>
应用程序.js
const title = React.createElement('h1', {}, 'Hi');
ReactDOM.render(title, document.querySelector('#app'));