1、tab切换

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <style>
        .item{
            width: 300px;
            background-color: #2459a2;
            height:38px;
            line-height: 38px;
        }
        .menu{
            float:left;
            border-right:1px solid blue;
            padding:0 10px;
            color: white;
            cursor: pointer;
        }
        .hide{
            display: none;
        }
        .active{
            background-color: blue;
        }
    </style>
</head>
<body>

<div class="item">
    <div class="menu active">菜单一</div>
    <div class="menu">菜单二</div>
    <div class="menu">菜单三</div>
</div>

<div class="content">
    <div class="info">内容一</div>
    <div class="info hide">内容二</div>
    <div class="info hide">内容三</div>
</div>


<script src="jquery.js"></script>
<script>
    $(".menu").click(function(){
        var i = $(this).index();
        $(this).addClass('active').siblings().removeClass('active');
        $(".info").eq(i).show().siblings().hide();
    });
</script>
</body>
</html>