循环利用removeChild（）和insertBefore（）将节点倒序失败
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>无标题文档</title>
</head>
<body>
<div id="content"><h1>html</h1><h1>php</h1><h2>javascript</h2><h1>jquery</h1><h1>java</h1></div>
<script type="text/javascript">
function clearText() {
var content=document.getElementById("content");
// 在此完成该函数
for(var i=content.childNodes.length-1;i>=0;i--){
var x=content.removeChild(content.childNodes[content.childNodes.length-1]);
//document.write(x.nodeName+"<br>"+x.nodeValue+"<br>"+x.nodeType+"<br>"+x.innerHTML+"<br><br>");
content.insertBefore(x,content.childNodes[0]);
}
}
</script>
<button onclick="clearText()">清除节点内容</button>
</body>
</html>
