JavaScript实现选项卡切换功能详解

<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <style>
        *{
            padding:0;
            margin:0;
        }
        .selectka {
            width:500px;
            height:400px;
            margin:auto;
            border:1px solid #09e1ff;
        }
        .left,.right{
            float:left;
            height:400px;
        }
        #menu{
            text-align: center;
            line-height: 80px;
            font-size: 20px;
            color:purple;
        }
        li{
            list-style: none;
        }
        #menu>li{
            width:100px;
            height:80px;
            border:1px dashed blueviolet;
            box-sizing: border-box;
        }
        .right{
            position: relative;
            width:399px;
            background: pink;
            margin-left:1px;
            text-align: center;
            font-size: 100px;
            line-height: 400px;

        }

        .right li{
            position: absolute;
            width:399px;
            height:400px;
            display: none;
        }
    </style>
</head>
<body>
<div class="selectka">
    <div class="left">
        <ul id="menu">
            <li class="menulist">衣服</li>
            <li class="menulist">美妆</li>
            <li class="menulist">包包</li>
            <li class="menulist">美食</li>
            <li class="menulist">首饰</li>
        </ul>
    </div>
    <div class="right">
        <ul>
            <li class="numlist">衣服</li>
            <li class="numlist">美妆</li>
            <li class="numlist">包包</li>
            <li class="numlist">美食</li>
            <li class="numlist">首饰</li>
        </ul>
    </div>
</div>
<script>
    var menu_list=document.getElementsByClassName("menulist");
    var num_list=document.getElementsByClassName("numlist");
    var moo=null;
    var yuu=null;
        for(var i=0;i<menu_list.length;i++) {
            menu_list[i].index = i;
            menu_list[i].onmouseenter = function () {
                /* console.log(this.index);*/   //this.index 为当前目标的索引值
                /* for(var k=0;k<num_list.length;k++){
                    num_list[k].style.display ="none";
                }
                num_list[this.index].style.display ="block";
            }*/
                if(yuu)yuu.style.background ="none";
                this.style.background ="yellow";
                yuu=this;
                 if(moo)moo.style.display="none";
                num_list[this.index].style.display = "block";
                moo = num_list[this.index];
        }
}
</script>
</body>
</html>