获取基于类的元素的jQuery索引

Question

I need to find the index of element with class "span":

<div>
<div>
    <div class="sd">
        <h2> H2 TEXT </h2>
        <span> SPAN </span>
        <span class="span"> SPAN </span>
    </div>
</div>
</div>

So i did:

var q = $('div > div > div.sd').find('.span').index();
alert(q)

This alerts "2" but the class is the first and only so it should alert "1". Is this because Jquery looks for the tag and not the class? I googled a lot and searched on stack but all examples include a click event which I don't want.

Live example: http://jsfiddle.net/jL7dsv5y/

Answer 1

If you apply .index() to a collection, and pass an element to it, it will return the position of that element within the collection. This will alert 0 because the .span element within the div is the first of all the .span elements in the document.

 var q = $(".span").index($('div > div > div.sd').find('.span')); alert(q); 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <div> <div> <div class="sd"> <h2> H2 TEXT </h2> <span> SPAN </span> <span class="span"> SPAN </span> </div> </div> </div>