使用 Jquery 获取列表项的索引
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Getting the index of a list item with Jquery
提问by Paul Sheldrake
I'm trying to find out the index number of the last list item but the jquery I'm using keeps returning -1. This is the JS and the html that I'm using.
我试图找出最后一个列表项的索引号，但我使用的 jquery 一直返回 -1。这是我正在使用的 JS 和 html。
var index = $('#imageThumbnails li:last').index(this);
<div id="imageThumbnails">
<ul class="gallery_demo_unstyled">
<li class="active"><img src="test-img.jpg" width="394" height="394" alt=" " /></li>
<li><img src="test-img2.jpg" width="394" height="394" alt=" " /></li>
<li><img src="test-img3.jpg" width="394" height="394" alt=" " /></li>
<li><img src="test-img4.jpg" width="394" height="394" alt=" " /></li>
<li><img src="test-img5.jpg" width="394" height="394" alt=" " /></li>
<li><img src="test-img6.jpg" width="394" height="394" alt=" " /></li>
<li><img src="test-img7.jpg" width="394" height="394" alt=" " /></li>
</ul>
</div>
Thanks for your help.
谢谢你的帮助。
回答by joshperry
You need to call index on the collection, passing in a sub-item of that collection.
您需要在集合上调用 index ，传入该集合的一个子项。
var items = $('#imageThumbnails li');
var lastItem = $('#imageThumbnails li:last');
var index = items.index(lastItem);
If you are in a click function handler you could do something like this:
如果您在单击函数处理程序中，您可以执行以下操作：
var items = $('#imageThumbnails li').click(function() {
var index = items.index(this);
// now that I know where I am, why am I here?
});
