小编pix*_*e54的帖子

我基本上都试图完成主题所暗示的内容,但我在警报中得到"未定义",我不完全确定原因.我对jquery相当新,所以,我可能有错误的语法,但不知道从哪里开始.我将发布我的两次尝试,这两次尝试都会在警报中产生"未定义"...

//In my first attempt, I'm trying to get the id of the inner a tag
<ul>
                <li id="l1" class="active"><a href="#c1">Samp 1</a></li>
                <li id="l2" class=""><a href="#c2">Samp 2</a></li>
                <li id="l3" class=""><a href="#c3">Samp 3</a></li>
        </ul>

var selected = $(".active).children("a").attr("id");
    alert(selected);

//In my second attempt, I'm trying to get the id of the currently selected li
    var selected = $(".active").attr("id");
    alert(selected);

尝试按升序对memnum下面的数组进行排序,我有点困惑哪个更好用... usort或array_multisort？我在想,因为它是多维的？有没有人有这样的例子？

Array
(
    [0] => Array
        (
            [memnum] => 3236467423
            [mid] => 1104881300  
            [fname] => JOHN        
            [lname] => DOE                 
            [add1] =>  OMITTED
            [add2] =>             
            [city] => CHESTERFIELD      
            [state] => MI
            [zip] => 48051
            [age] => 50 
        )
    [1] => Array
        (
            [memnum] => 3258467922
            [mid] => 1105121457  
            [fname] => JANE        
            [lname] => DOE                 
            [add1] =>  OMITTED
            [add2] =>             
            [city] => CHESTERFIELD      
            [state] => MI
            [zip] => 48051
            [age] => 50 
        )
    [2] => Array
        (
            [memnum] => 3237769108
            [mid] …