filter:过滤当前元素自身
not:filter的反义词
has:当前元素里面的东西
<body>
<div class="box">div1</div>
<div>div2</div>
<div>
<span class="box">div3</span>
</div>
<script>
$(function(){
$('div').filter('.box').css('background','red');
// div1的背景为红色
$('div').not('.box').css('background','green');
//div2和div3背景为green
$('div').has('.box').css('color','yellow');
//div3的颜色为yellow
})
</script>
</body>