<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>nextSibling</title>
</head>
<body>
<ul id="u1">
<li id="a">javascript</li>
<li id="b">jquery</li>
<li id="c">html</li>
</ul>
<ul id="u2">
<li id="d">css3</li>
<li id="e">php</li>
<li id="f">java</li>
</ul>
<script type="text/javascript">
var ul = document.getElementsByTagName('ul')[0].firstChild;
var li = get_notext(ul);
document.write(li.nodeName + "=" + li.innerHTML + "<br/>");
function get_notext(li) {
while (li.nodeType != 1) {
x = li.nextSibling;
}
return x;
}
function get_nextSibling(li) {
var x = li.nextSibling
while (x.nodeType != 1) {
x = x.nextSibling;
}
return x;
}
var nextLi = get_nextSibling(li);
if (nextLi != null) {
document.write(nextLi.nodeName + "=" + nextLi.innerHTML + "<br/>");
} else {
document.write("这已经是最后一个节点")
}
function get_prevSibling(li) {
var x = li.previousSibling;
while (x.nodeType != 1) {
x = x.previousSibling;
}
return x;
}
var u2li = document.getElementById("u2").lastChild;
var prevLi = get_prevSibling(u2li);
if (prevLi != null) {
document.write(prevLi.nodeName + "=" + prevLi.innerHTML + "<br/>");
} else {
document.write("这已经是最后一个节点")
}
</script>
</body>
</html>你while里面没有写break，所以就无限次执行了呀