获取ul中活动li的值

Question

我试图从jqvalue中的ul获取活动li,但我得到的只是null.我也尝试用控制台目录来写ul的值(尝试和模拟php的var_dump但是没有发生任何事情)

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

将类更改为ID即li.creditto li#credit和interesttodata-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的

$(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;

}