在线运行代码 - 菜鸟教程

<!DOCTYPE html>
<html>
<head> 
<meta charset="utf-8"> 
<title>菜鸟教程(cainiaoplay.com)</title>
</head>
<body>

<p>单击按钮将HTML标题设置从1到6的样式显示</p>
<button onclick="myFunction()">点我</button>
<div id="demo"></div>
<script>
function myFunction(){
	var x="",i;
	for (i=1; i<=6; i++){
		x=x + "<h" + i + ">Heading " + i + "</h" + i + ">";
	}
	document.getElementById("demo").innerHTML=x;
}
</script>

</body>
</html>

源代码

动行结果