php中如何去除二维数组的某个字段

php中怎么去除二维数组的某个字段？
1，需求：有如下二维数组，怎么去除此数组的字段"on" 生成一个新数组 $arr2
$arr = array("net" => array("on", "11", "101", "1001"),
"login" => array("on", "10001","100001","1000001"));

$arr2 = array("net" => array( "11", "101", "1001"),
"login" => array("10001","100001","1000001"));
或者遍历时候去掉on也行
2，能达到这样的效果也可以
$arr = array("net" => array("on","1", "2","4"),
"login" => array("on","10001","100001","10000001")
);
$str ='';
foreach ($arr as $key=>$value){
foreach ($value as $k =>$v){
$str=$str|$v;
}
}
var_dump($str);
//值运算后面数字的或运算得到值$str，"on"这个字段是不能参加运算的



------解决思路----------------------
1、这样去掉

$arr = array(
  "net" => array("on", "11", "101", "1001"),
  "login" => array("on", "10001","100001","1000001")
);

array_walk($arr, function(&$t) {
  $t = array_diff($t, array('on'));
});

print_r($arr);

Array
(
    [net] => Array
        (
            [1] => 11
            [2] => 101
            [3] => 1001
        )

    [login] => Array
        (
            [1] => 10001
            [2] => 100001
            [3] => 1000001
        )

)

2、这样运算

$arr = array(
  "net" => array("on", "11", "101", "1001"),
  "login" => array("on", "10001","100001","1000001")
);

$str ='';
foreach ($arr as $key=>$value){
    foreach ($value as $k =>$v){
        if($v != 'on') $str = $str
------解决思路----------------------
$v;
    }
}
var_dump($str);

string(7) "1111111"

------解决思路----------------------

$arr = array("net" => array("on", "11", "101", "1001"),
    "login" => array("on", "10001","100001","1000001"));

delon($arr);
print_r($arr);


function delon(&$arr){
	foreach($arr as $key=>&$val){
		foreach($val as $k=>$v){
			if($v=='on'){
				unset($val[$k]);
			}
		}
	}
}

Array
(
[net] => Array
(
[1] => 11
[2] => 101
[3] => 1001
)

[login] => Array
(
[1] => 10001
[2] => 100001
[3] => 1000001
)

)