jquery nth-child()选择器的简单应用

<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： 
 代码如下:

<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 
//www.gxlcms.com/css/28294.html 
//www.gxlcms.com/article/23617.htm
效果图如下：