<ul class="qq">
<li id="li1" class="ss">sdf</li>
<li id="li2">sdf</li>
<li id="li3" class="ss">sdf</li>
<li id="li4" class="ss">sdf</li>
<li id="li5">sdf</li>
<li id="li6" class="ss">sdf</li>
<li id="li7">sdf</li>
</ul>
<a href="#" id="aa">dfgdfg</a>点击aa的时候获取li中样式为ss的li的id
<li id="li1" class="ss">sdf</li>
<li id="li2">sdf</li>
<li id="li3" class="ss">sdf</li>
<li id="li4" class="ss">sdf</li>
<li id="li5">sdf</li>
<li id="li6" class="ss">sdf</li>
<li id="li7">sdf</li>
</ul>
<a href="#" id="aa">dfgdfg</a>点击aa的时候获取li中样式为ss的li的id
$(".ss li").attr("id");