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Correction status：qualified
Teacher's comments：
Collection
Collection
jQuery获取滚动值
运用到 scroll 事件方法
scrollTop 获取 滚动条到顶部的的垂直高度（即网页被卷上去的高度）
<!DOCTYPE html>
<html>
<head>
<title>获取滚动值案例</title>
<link rel="icon" type="image/x-icon" href="images/2.png">
<script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
<style type="text/css">
*{margin: 0;padding: 0;}
.content{ width:100%;height:60px;
background: rgba(160,3,162,0.1);
box-shadow: 1px 3px 7px #ccc;
line-height: 60px;
position: fixed;
}
.content_2{background: rgba(160,3,162,0.4)}
form{width: 500px;height: 35px;position: relative;margin: 0 auto;}
input{width:480px;height: 35px;border-radius: 20px;border:none;outline: none;padding-left:20px;}
button{width: 70px;height:35px;order:none;
border-top-right-radius: 20px;border-bottom-right-radius: 20px;border: none;
color: #fff;position: absolute;right:0;top:14px;
outline: none;font-weight: bold;
background: rgba(160,3,162,0.4);
}
[placeholder]{color:rgba(160,3,162,0.6)}
.pic{width: 70%;height: 580px;background: url(images/3.jpg);margin: 0 auto;}
.box{width: 70%;height:1200px;background:rgba(108,108,106,0.1);margin: 0 auto; }
</style>
</head>
<body>
<!-- 顶部导航 -->
<div class="content">
<form>
<input type="text" placeholder="# 请输入关键词 #">
<button>全网搜</button>
</form>
</div>
<!-- 轮播图 -->
<div class="pic"></div>
<!-- 页面详情 -->
<div class="box"></div>
<script>
$(function(){
$(window).scroll(function(){
if($(window).scrollTop() > 35){
$('.content').css('display','none');
}else{
$('.content').css('display','block');
};
if($(window).scrollTop() > 580){
//.addClass()添加Class removeClass()清除
$('.content').addClass('.content_2').css('display','block');
}else{
$('.content').removeClass('.content_2');
};
});
})
</script>
</body>
</html>点击选择效果（单行不可多选）效果
原理：给点击的按钮添加 css效果（边框，字体颜色，等），
匹配span中是否含有 Class为 select ，含有就清除 ，没有就添加select 同时匹配同级span 清除其他span的选择样式select
用到的方法：
hasClass（'select'）是否含有class为 select
removeClass('select') 清除class为 select
addClass('select') 添加class为 select
siblings（）匹配同级元素
<!DOCTYPE HTML>
<html>
<head>
<title>点击商品选中效果</title>
<meta charset="utf-8"/>
<link rel="icon" type="image/x-icon" href="images/2.png">
<script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
<style type="text/css">
* {margin: 0px auto;padding: 0px;}
.top {width: 402px;height: 35px;
line-height: 35px;text-align:center;
margin-top: 50px;
background: #C40000;color:#fff;
}
.main {width: 400px;height: 400px;border: 1px solid #C40000;}
p {width: 400px;height: 26px;margin-top:10px;}
b {width: 90px;height: 26px;
line-height: 26px;text-align: center;
font-size: 12px;color:#838383;
border: 1px solid #ccc;
float: left;margin-left: 5px;}
span {width: 90px;height: 26px;line-height: 26px;
text-align: center;font-size: 12px;
color:#838383;border: 1px solid #ccc;
display: block;float: left;margin-left: 5px;}
span:hover {cursor: pointer;}
button {width: 120px;height: 35px;background: #C40000;color: white;border: 0px;}
button:hover {cursor: pointer;}
.notice{
border:0px;
}
.select {
border: 2px solid red;
line-height: 24px;
width:88px;
}
</style>
</head>
<body>
<div class="top">请选择信息后加入购物车</div>
<div class="main">
<p class="item" name="version">
<b class="notice">版本</b>
<span>ONE A2001</span>
<span>ONE A0001</span>
<span>ONE A1001</span>
</p>
<p class="item" name="color">
<b class="notice">机身颜色</b>
<span>白色</span>
<span>黑色</span>
<span>金色</span>
</p>
<p class="item" name="type">
<b class="notice">套餐类型</b>
<span>标配</span>
<span>套餐一</span>
<span>套餐二</span>
</p>
<p class="item" name="ram">
<b class="notice">运行内存</b>
<span>2GB</span>
<span>3GB</span>
<span>4GB</span>
</p>
<p class="item" name="rom">
<b class="notice">机身内存</b>
<span>16GB</span>
<span>32GB</span>
<span>64GB</span>
</p>
<p class="item" name="location">
<b class="notice">产地</b>
<span>中国大陆</span>
<span>港澳台</span>
</p>
<p class="item" name="price">
<b class="notice">价格</b>
<span>999元抢购</span>
</p>
<p class="item1" name="num">
<b class="notice">数量</b>
<input type="number" value="1" style="width:40px;height:26px;">
</p>
<p style="margin-top:30px;margin-left:95px;">
<button class="bu1" id='sub'>加入购物车</button>
</p>
</div>
<script>
$(function(){
//hasClass() 方法检查被选元素是否包含指定的 class 返回值：布尔值。
$('span').click(function(){
if($(this).hasClass('select')){ //匹配span中是否含有class为select
$(this).removeClass('select');//有就清除
}else{
$(this).addClass('select').siblings('span').removeClass('select');
//没有就添加上select的class名，同时匹配同级span，清除同级其他span中的选中样式
// sinlings() 匹配同级(兄弟) 含有class类的元素
}
});
})
</script>
</body>
</html>点击 "运行实例" 按钮查看在线实例