今天项目中遇到过一个这样的问题，就是希望读出来的文章列表能够每隔五个加一个分割条，而不是每个都加。
通过网上咨询使用这个选择器便很容易的解决。特此记录一下。
下面是主要的代码
js脚本：
<script type="text/javascript">
$(document).ready(
function () {
//每隔五行给li加一个样式
$('.article_li li:nth-child(5n)').addClass('liborder');
$('.article_li li:last').addClass('liborder');
}
);
</script>
html代码：
<ul class="article_li">
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点物业税:长沙暂不试点</a>
</li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
<li>
<label class="datename">
<span>2010-06-12 08:37:59 </span>
</label>
<a href="/a/xinwenzixun/caishuidongtai/20100612/2323.html">物业税:长沙暂不试点</a> </li>
</ul>
具体的用法这里就不写了，大家可以参考
http://www.cnblogs.com/Elgin/archive/2010/05/24/1742563.html
http://www.2ndvisual.com/xhtml/css/20616.html
效果图如下：
