我有動(dòng)態(tài)生成的 div 部分，類(lèi)名以數(shù)字結(jié)尾。我想從類(lèi)屬性中獲取數(shù)字我想從類(lèi) submit-1 (1),submission-2 (2) 中獲取數(shù)字，并像在代碼段中一樣嘗試。我發(fā)現(xiàn)了錯(cuò)誤未定義的匹配函數(shù)。如何從類(lèi)屬性中獲取數(shù)字$(document).ready(function(){  var num = $('.submission-').attr('class').match(/\d+$/)[0];  console.log(num);});<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script><div class="webform submission-1">   <span class="first">1</span>   <span class="second">11</span> </div><div class="webform submission-2">   <span class="first">2</span>    <span class="second">22</span> </div><div class="webform submission-3">   <span class="first">3</span>    <span class="second">33</span>  </div><div class="webform submission-4">   <span class="first">4</span>    <span class="second">44</span>  </div><div class="webform submission-12">   <span class="first">12</span>     <span class="second">1212</span>  </div>