Javascript XML按属性名称列出的结果数

我正在使用以下XML文件

     <OnThisDate date="2013-02-22">
      <event jobnumber="14434" allocated="1" name="ADI UK ">
        <i1001 driverID="30" driverName="None None" groupname="i100"/>
        <i251 driverID="0" driverName="" groupname="i25"/>
        <i252 driverID="0" driverName="" groupname="i25"/>
      </event>

      <event jobnumber="14559" allocated="1" name="Travel">
        <i1006 driverID="46" driverName="Martin Macklin" groupname="i100"/>
      </event>

      <event jobnumber="14560" allocated="1" name="Travel">
        <i1005 driverID="0" driverName="" groupname="i100"/>
      </event>

      <event jobnumber="14690" allocated="1" name="Travel">
        <i253 driverID="0" driverName="" groupname="i25"/>
      </event>

      <event jobnumber="14695" allocated="1" name="Holiday">
        <i602 driverID="10" driverName="Alan Linney " groupname="i60"/>
      </event>

      <event jobnumber="13595" allocated="1" name="Sandown Park Racecourse">
        <i1002 driverID="6" driverName="Simon Latcham" groupname="i100"/>
      </event>

      <event jobnumber="14447" allocated="1" name="Sandown Racecourse">
        <i125 driverID="35" driverName="Carl Boxall" groupname="i12"/>
      </event>

      <event jobnumber="14030" allocated="1" name="Warwick Racecourse">
         <i601 driverID="5" driverName="Tom Robson" groupname="i60"/>
      </event>
     </OnThisDate>

但我不知道如何让它的其余部分发挥作用

---

需要帮忙吗，提前感谢

获取具有特定组名的所有元素的计数：

var groupname = "i25";
var count = $(data).find('*[groupname="' + groupname + '"]').length;

旁注：

.size（）

从jQuery 1.8开始就不推荐使用。建议改用

.length

var groupname = "i25";
var count = $(data).find('*[groupname="' + groupname + '"]').length;