<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>css选择器</title>
<script type="text/javascript" src="jquery-1.7.min.js"></script>
<style type="text/css">
.one {border: 1px solid #03F; float: left; margin: 1em; padding: 1.5em; width: 106px; }
.two {background-color: #FC0; }
.three {background-color: #FCF; }
</style>
<script type="text/javascript">
$(document).ready(function() {
$("*").css("font-size", "12px");
$("div").addClass("one");
$("#div1").addClass("two");
$("#div2, #div3").addClass("three");
$("h3, p").css("color", "red").attr("align", "center");
$("#span1").html("本网页中同时应用one类的元素一共有" + $(".one").length + "个" + ",同时应用one类和three类的元素共有" + $(".one.three").length + "个");
});
</script>
</head>
<body>
<h3>这是标题中的文本</h3>
<p><span id="span1"></span></p>
<div id="div1">div元素：id属性为div1.</div>
<div id="div2">div元素：id属性为div2.</div>
<div id="div3">div元素：id属性为div3.</div>
</body>
</html>
