小编ojo*_*ual的帖子

我有一个 HTML 如下：

<ul class="thumbnails">
    <li><a class="thumbnail" href="http://localhost/upload/image/cache/catalog/demo/canon_eos_5d_1-500x500.jpg" title="Canon EOS 5D"><img src="http://localhost/upload/image/cache/catalog/demo/canon_eos_5d_1-228x228.jpg" title="Canon EOS 5D" alt="Canon EOS 5D"></a></li>
    <li class="image-additional"><a class="thumbnail" href="http://localhost/upload/image/cache/catalog/demo/canon_eos_5d_2-500x500.jpg" title="Canon EOS 5D"> <img src="http://localhost/upload/image/cache/catalog/demo/canon_eos_5d_2-74x74.jpg" title="Canon EOS 5D" alt="Canon EOS 5D"></a></li>
    <li class="image-additional"><a class="thumbnail" href="http://localhost/upload/image/cache/catalog/demo/canon_eos_5d_3-500x500.jpg" title="Canon EOS 5D"> <img src="http://localhost/upload/image/cache/catalog/demo/canon_eos_5d_3-74x74.jpg" title="Canon EOS 5D" alt="Canon EOS 5D"></a></li>
</ul>

我想得到src valueimg。我使用了以下代码：

var imgTag =  $('.thumbnail').attr("href");
        console.log(imgTag);

它给出了href但a tag我想要 img 标签的 src 在a tag我应该做什么修改之后？