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

$arr = array(<br />  "net" => array("on", "11", "101", "1001"),<br />  "login" => array("on", "10001","100001","1000001")<br />);<br /><br />array_walk($arr, function(&$t) {<br />  $t = array_diff($t, array('on'));<br />});<br /><br />print_r($arr);

Array<br />(<br />    [net] => Array<br />        (<br />            [1] => 11<br />            [2] => 101<br />            [3] => 1001<br />        )<br /><br />    [login] => Array<br />        (<br />            [1] => 10001<br />            [2] => 100001<br />            [3] => 1000001<br />        )<br /><br />)<br />

2、这样运算

$arr = array(<br />  "net" => array("on", "11", "101", "1001"),<br />  "login" => array("on", "10001","100001","1000001")<br />);<br /><br />$str ='';<br />foreach ($arr as $key=>$value){<br />    foreach ($value as $k =>$v){<br />        if($v != 'on') $str = $str<br><font color='#FF8000'>------解决思路----------------------</font><br>$v;<br />    }<br />}<br />var_dump($str);

string(7) "1111111"<br />

------解决思路----------------------

<br />$arr = array("net" => array("on", "11", "101", "1001"),<br />    "login" => array("on", "10001","100001","1000001"));<br /><br />delon($arr);<br />print_r($arr);<br /><br /><br />function delon(&$arr){<br />	foreach($arr as $key=>&$val){<br />		foreach($val as $k=>$v){<br />			if($v=='on'){<br />				unset($val[$k]);<br />			}<br />		}<br />	}<br />}<br />

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

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

)