Jquery实现全选和取消全选的方法

<input type="checkbox" id="all" />全选<br />  
<input type="checkbox" name="permission" />添加权限<br />  
<input type="checkbox" name="permission" />修改权限<br />  
<input type="checkbox" name="permission" />权限列表<br />  
<script>
    $("#all").on('click',function() {
        $("input[name='permission']").prop("checked", this.checked);
    });

    $("input[name='permission']").on('click',function() {
        var $subs = $("input[name='permission']");
        $("#all").prop("checked" , $subs.length == $subs.filter(":checked").length ? true :false);
    });
</script>