【第一步】先写一个测试，hello world
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>yma</title>
<script src="https://unpkg.com/vue@next"></script>
</head>
<body>
<div id = "root"></div>
</body>
<script>
Vue.createApp({
template:'<div>hello</div>'
}).mount('#root');
</script>
</html>效果如下
【原理】