<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
.outer{
height: 1000px;
width: 100%;
}
.menu{
float: left;
background-color: beige;
width: 30%;
height: 500px;
}
.content{
float: left;
background-color: rebeccapurple;
width: 70%;
height: 500px;
}
.title{
background-color: aquamarine;
line-height: 40px;
}
.hide{
display: none;
/*隐藏*/
}
</style>
</head>
<body>
<div class="outer">
<div class="menu">
<div class="item">
<div class="title" onclick="show(this)">菜单一</div>
<div class="con">
<div>111</div>
<div>111</div>
<div>111</div>
</div>
</div>
<div class="item">
<div class="title"onclick="show(this)">菜单二</div>
<div class="con hide"><!--隐藏起来，一个类名2个名字功能不同-->
<div>222</div>
<div>222</div>
<div>222</div>
</div>
</div>
<div class="item">
<div class="title"onclick="show(this)">菜单三</div>
<div class="con hide">
<div>333</div>
<div>333</div>
<div>333</div>
</div>
</div>
</div>
<div class="content"></div>
</div>
<script src="jquery-3.3.1.min.js"></script>
<script>
function show(hello) {//jquery对象取的方法,不加引号-----$(hello)
$(hello).next().removeClass("hide");//移除hide名字，显示
$(hello).parent().siblings().children(".con").addClass("hide");//加上hide名字重新隐藏item
//拿到菜单一二三标签，找到父标签item,找到sibilings标签即另外2个item标签，
// 对另2个item标签children标签找到icon标签，加上类名hide
}
</script>
</body>
</html>
