<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<script type="text/javascript" src="jquery-1.10.1.min.js"></script>
</head>
<body>
<script>
$(function()
      {
/*$("span").eq(0).prop("demo","it666");
        $("span").eq(1).prop("demo","lnj");
        document.write($("span").prop("demo"));//默认是下标0*/
document.write($("input").prop("checked"));
//使用prop时时true或者false
document.write($("input").attr("checked"));
//使用attr时时check或者undefined
      });
</script>
<span class="span1" name="it666"></span>
<span class="span2" name="lnj"></span>
<input type="checkbox">
</body>
</html>