jquery - 获取ul中active li的值

Question

我试图从 jqvalue 中的 ul 获取事件 li，但我得到的只是 null。我还尝试使用控制台目录写入 ul 的值(尝试模拟 php 的 var_dump 但那里也没有发生任何事情

这是我的 jfidde:http://jsfiddle.net/#&togetherjs=MDbkUMciB7

这是代码

function monthly_payment(){
    var interest = $('ul.credit').find('li.active').data('interest');
    console.dir($('ul.credit'));
alert(interest);
      // var iinterest   = interest_rate / 1200;


}


<ul id="credit">
<li interest = "0.056" class="active"><a href="#"><span id="excellent" class="0.056">excellent</span></a></li>
<li interest = "0.099"><a href="#"><span id="good" class="0.099">good</span></a></li>                       <li interest = "0.169"a href="#"><span id="fair" class="0.169">fair</span></a></li>
<li interest = 0.299><a href="#"><span id="bad" class="0.299">bad</span></a></li>
</ul>

Answer 1

将 class 更改为 ID，即 li.credit 更改为 li#credit，将 interest 更改为 data-interest

HTML

<ul id="credit" name="credit">
            <li data-interest = "0.056" class="active"><a href="#"><span id="excellent" class="0.056">excellent</span></a></li>
            <li data-interest = "0.099"><a href="#"><span id="good" class="0.099">good</span></a></li>                      
           <li data-interest = "0.169"><a href="#"><span id="fair" class="0.169">fair</span></a></li>
            <li data-interest = 0.299><a href="#"><span id="bad" class="0.299">bad</span></a></li>
        </ul>

JQuery

$(function() {
    monthly_payment();
 });


function monthly_payment(){
    var interest = $('ul#credit').find('li.active').data('interest');
    alert(interest);
   console.dir($('ul.credit'));
       var iinterest   = interest_rate / 1200;
       payment = principal * interest / (1 - (Math.pow(1/(1 + interest), monthly_period)));
       payment = Math.round(payment * 100) / 100;
       return payment;

}