navbar-header的div中,为什么button标签写在a标签之前
第一种:
<div class="navbar-header">
<button class="navbar-toggle" type="button" data-toggle="collapse" data-target=".navbar-responsive-collapse">
<span class="sr-only">Toggle Navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>//这个是一横的图标
</button>
<a href="##" class="navbar-brand">慕课网</a>
</div>
第二种
<div class="navbar-header">
<a href="##" class="navbar-brand">慕课网</a>
<button class="navbar-toggle" type="button" data-toggle="collapse" data-target=".navbar-responsive-collapse">
<span class="sr-only">Toggle Navigation</span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>
<span class="icon-bar"></span>//这个是一横的图标
</button>
</div>
我用chrome试了一下,没有看出区别,还是说这是一种规定?