Level selector
##$(s1 s2) [Father and Son]
<div> <span></span> <p> <span></span> </p> </div> <span></span>
$(s1 > s2) [parent and child]
##Direct child element selector: in s1 Internally obtain the child element node of s2
$("div > span")
<div> <span></span> <p> <span></span> </p> <span></span> </div> <span></span>
$(s1 + s2) [Brother]
Direct sibling selector: Get the s2 node of the first sibling relationship immediately after s1. There cannot be any other tags between s1 and s2, otherwise Not working
$("div + span")
<div> <span></span> <p> <span></span> </p> <span></span> </div> <span></span> <span></span> <div></div> <span></span>
Subsequent all sibling relationship node selectors: Get all s2 nodes of sibling relationships behind s1
<div> <span></span> <p> <span></span> </p> <span></span> </div> <span></span> <span></span> <p></p> <span></span>
<!DOCTYPE html>
<html>
<head>
<title>php.cn</title>
<meta charset="utf-8" />
<script src="http://libs.baidu.com/jquery/1.10.2/jquery.min.js"></script>
<script >
function f1(){
//$(s1 s2)
$('div span').css('background-color','blue');
//$(s1 > s2)
$('div > span').css('background-color','green');//张飞 关羽
//$(s1 + s2) 紧紧挨着的
$('div + span').css('background-color','red');
//$(s1 ~ s2)
$('div ~ span').css('background-color','brown');
}
</script>
</head>
<body>
<h2>层次选择器</h2>
<div>
<span>北京</span>
<p>
<span>上海</span>
</p>
<span>深圳</span>
</div>
<p>南京</p>
<span>杭州</span>
<p>厦门</p>
<span>天津</span>
<div>重庆</div>
<span>合肥</span>
<input type="button" value="触发" onclick="f1()" />
</body>
</html>Note: Please comment out the other three of the four selectors. Test one by one
