<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>替换子节点replaceChild()</title>
<!--
node.replaceChild(a,b)将父节点node的子节点b替换为子节点a
-->
</head>
<body>
<div>我要被替换了</div>
<script>
var div=document.getElementsByTagName("div")[0];//获取子节点
var newdiv=document.createElement("div");//创建新的子节点
newdiv.innerHTML="我是新的,我替换了老的div";//为新的子节点添加内容
document.body.replaceChild(newdiv,div);//替换
</script>
</body>
</html>