<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>JS Bin</title>
<style>
.box{
width: 300px;
background: yellow;
padding: 0;
}
ul>li{
list-style: none;
padding: 10px;
margin: 5px;
background: pink;
}
ul>li.hover{
background: blue;
}
</style>
</head>
<body>
<ul class="box">
<li>111</li>
<li>222</li>
<li>333</li>
</ul>
<script>
var Obox=document.querySelector(".box");
Obox.addEventListener("mouseover",function(e){
for (var i=0;i<this.children.length;i++) {
this.children[i].classList.remove("hover");
}
e.target.classList.add("hover");
});
</script>
</body>
</html>
优化代码
图片.png
