jquery类选择器无法取得对象问题原因

jquery类选择器无法取得对象问题原因

<html>
    <script type="text/javascript" src="jquery-1.9.1.js"></script>
<body>

<table>
<tr class="bottom b-fffdee xinghao68">
            <td> </td>
            <td class="t-left">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
            <a href="http://localhost:8080/BNCAR2/partsDetailAction?id=58" class="fc-blue"><img src="picture/parts/2014/1/13/138961178380789969.jpg" width="44" height="44" /> 单件商品2</a></td>
            <td></td>
             <td>            
                </td> 
            <td></td>
            <td></td>
          </tr>
          
          <tr class="bottom b-fffdee xinghao68">
            <td> </td>
            <td class="t-left">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
            <a href="http://localhost:8080/BNCAR2/partsDetailAction?id=55" class="fc-blue"><img src="picture/parts/2014/1/9/138924733778756518.jpg" width="44" height="44" /> QQQQ</a></td>
            <td></td>
             <td>            
                </td> 
            <td></td>
            <td></td>
          </tr>
          
          <tr class="bottom b-fffdee xinghao68" >
            <td> </td>
            <td class="t-left">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
            <a href="http://localhost:8080/BNCAR2/partsDetailAction?id=45" class="fc-blue"><img src="picture/parts/none.jpg" width="44" height="44" /> aa</a></td>
            <td></td>
             <td>            
                </td> 
            <td></td>
            <td></td>
          </tr>
          </table>
</body>

<script type="text/javascript">
    $(function(){
            alert("AAA:"+$(".xinghao68"));
            alert("BBB:"+$(".xinghao68").length);
            $(".xinghao68").each(function(){
                    alert($(this).text());
                    
                });
        
        });
</script>

</html>

如果TR行class写成:<tr class="bottom b-fffdee" class="xinghao68">,这样通过类选择器是取不到的,需要注意代码结构的严谨性~!!!
应用:在商城类网站购物车中,组合产品下面还有子产品,在移出组合产品的时候需要同时将子产品移出,可以通过设置一个class来获取一个集合,each遍历移出每一个达到效果。