<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<script type="text/javascript" src="../js/jquery-1.8.2.js"></script>
</head>
<body>
<input type="checkbox" value="篮球" checked="checked">篮球</input>
<input type="checkbox" value="排球">排球</input>
<input type="checkbox" value="羽毛球" >羽毛球</input>
<input type="checkbox" value="乒乓球">乒乓球</input>
<input type="button" value="选中个数"></input>
<input type="button" value="依次显示选中的value"></input> <script type="text/javascript">
$(":button:first").click(function(){ alert($(":checkbox:checked").size());
});
$(":button:last").click(function(){
$(":checkbox[checked='checked']").each(function(){
alert($(this).val());
}); });
</script>
</body>
</html>