<html>
<head>
<script src="https://ajax.aspnetcdn.com/ajax/jQuery/jquery-3.4.1.min.js"></script>
</head>
<body>
<h1>设置 HTML</h1>
<div id="01">
<h2 >Hello World!</h2>
</div>
<div id="02">
<h2 >Hello Sweden!</h2>
</div>
<p id="demo"></p>
<script>
$(document).ready(function() {
var myElement = $("#02");
myElement.html("<p>Hello World!</p>");
});
</script>
</body>
</html>