<li class="cwhite" value="02" id="02" onclick="getQuestionList('02',this);">數學</li>
var subjectCode = $(obj).find(".bd.subject li[class='cwhite active']").val();
這種方法會把02前面的0自動截取
var subjectCode = $(obj).find(".bd.subject li[class='cwhite active']").attr("value");
用attr("value")就不會截取了