直接借鉴的 ids拼接

  function _getIds(selectedIds, targetType){
           var ids = "";
           var $box = targetType == "dialog" ? $.pdialog.getCurrent() : navTab.getCurrentPanel();
           $box.find("input:checked").filter("[name='"+selectedIds+"']").each(function(i){  //注意each
               var val = $(this).val();
               ids += i==0 ? val : ","+val; //重点
            });
                return ids;
        }

来自为知笔记(Wiz)