<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title> Subclass selector and descendant selector </ title>
</head>
<body>
<div id="father">
<div>11</div>
<div>22
<p>111</p>
<p>222</p>
<p>333</p>
</div>
<div>33</div>
<div>44</div>
<div>55</div>
<p>66</p>
<p>77</p>
<p>88</p>
</div>
<script src="jquery-1.12.4.js"></script>
<script>
$(function(){
// $ ("s1, s2") // Union selector
// $ ("s1 s2") // Descendant selector
// $ ("s1> s2") // Subband selector
// $("li.green")
// $ ("s1s2") // Intersection selector
$("#father p").css("backgroundColor","red");
});
</script>
</body>
</html>