<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<input type="button" value="变色" id="bt"/>
<ul id="uu">
<li>红烧鲤鱼</li>
<li>糖醋排骨</li>
<li>红烧茄子</li>
<li>酸辣土豆丝</li>
<li>麻辣小龙虾</li>
<li>东北烤冷面</li>
<li>陕西肉夹馍</li>
<li>云南过桥米线</li>
</ul>
<script src="common.js"></script>
<script>
//隔行变色
my$("bt").onclick = function () {
var count = 0;//记录li的个数
//获取ul中所有的子节点
var nodes = my$("uu").childNodes;
for (var i = 0; i < nodes.length; i++) {
//判断这个节点是不是li
if (nodes[i].nodeType == 1 && nodes[i].nodeName == "LI") {
nodes[i].style.backgroundColor = count % 2 == 0 ? "red" : "yellow";
count++;
}
}
};
</script>
</body>
</html>