<ul class="u">
<li> <span>1</span></li>
<li> <span>2</span></li>
<li> <span>3</span></li>
</ul>
$('ul li:last-child') 能匹配到
$('ul span:last-child') 匹配不到
why?
span
不在同一个li
里,彼此不是同级
<ul class="u">
<li> <span>1</span></li>
<li> <span>2</span></li>
<li> <span>3</span></li>
</ul>
$('ul li:last-child') 能匹配到
$('ul span:last-child') 匹配不到
why?
span
不在同一个li
里,彼此不是同级