jquery全选反选

<script type="text/javascript">
        $(function () {
            $("input[name='hobby']").click(function () {
                $("input[name='hobby']:checked").length == $("input[name='hobby']").length ? $("#checkAll").attr("checked", true) : $("#checkAll").attr("checked", false);
            });
            $("#checkAll").click(function () {
                $("input[name='hobby']").attr("checked", this.checked);
            });
    $("#checkReverse").click(function () {
var arr = jQuery("input[name='hobby']");
            for(var i=0;i<arr.length;i++){
            arr[i].checked = ! arr[i].checked;
         }
     });
        });
</script>
<form action="test.htm" method="post" id="form" name="form">
<input id="checkAll" type="checkbox" />全选/ <input id="checkReverse" type="checkbox"/>反选
<br />
<input type="checkbox" name="hobby" />
<input type="checkbox" name="hobby" />
<input type="checkbox" name="hobby" />
<input type="checkbox" name="hobby" />
<input type="checkbox" name="hobby" />
</form>