Moving around key order in a multi-dimensional array

Question

How can I "reorder" the keys in a multi-array? For example, I have:

$arr["abc"][0] = "val1";
$arr["abc"][1] = "val2";
$arr["abc"][2] = "val3";
$arr["xyz"][0] = "val4";
$arr["xyz"][1] = "val5";
$arr["xyz"][2] = "val6";

And I want it to be:

$arr[0]["abc"] = "val1";
$arr[0]["xyz"] = "val4";
$arr[1]["abc"] = "val2";
$arr[1]["xyz"] = "val5";
$arr[2]["abc"] = "val3";
$arr[2]["xyz"] = "val6";

My current effort is:

foreach ($arr as $param => $num) foreach ($num as $val) $newArr[$num][$param] = $val;

but it doesn't seem to be working. Any help would be appreciated.

EDIT: Specifically, I'm trying to loop through all elements submitted on $_FILES, as they all need the same thing done to them. By default, when there is more than one <input type="file" name="filedata[]" /> in a form, they go to $_FILES["filedata"]["name"][$index]. ("name" or any other parameter), so I cant just loop through every $_FILES["filedata"] to get at everything; thus, I need the keys of $_FILES["filedata"] reversed.

Answer 1

I think you need to still grab the keys in the second foreach. Try something like:

foreach($arr as $k1 => $v1) {
  foreach ($v1 as $k2 => $v2) {
    $newArray[$k2][$k1] = $v2
  }
}

Answer 2

It sounds like what you might be looking for is array_flip. See here:

http://us3.php.net/manual/en/function.array-flip.php

Answer 3

Straightforward enough with two foreach loops:

// Original version:
$arr = array();
$arr["abc"][0] = "val1";
$arr["abc"][1] = "val2";
$arr["abc"][2] = "val3";
$arr["xyz"][0] = "val4";
$arr["xyz"][1] = "val5";
$arr["xyz"][2] = "val6";

print_r($arr);

$newarray = array();
// Swap around the keys
foreach ($arr as $key1 => $val1) {
    foreach ($val1 as $key2 => $val2) {
     $newarray[$key2][$key1] = $val2;  
    }
}
print_r($newarray);

Here's the display:

// Display of $arr:
//Array
//(
//    [abc] => Array
//        (
//            [0] => val1
//            [1] => val2
//            [2] => val3
//        )
//
//    [xyz] => Array
//        (
//            [0] => val4
//            [1] => val5
//            [2] => val6
//        )
//
//)



//Display of $newarray:
//Array
//(
//    [0] => Array
//        (
//            [abc] => val1
//            [xyz] => val4
//        )
//
//    [1] => Array
//        (
//            [abc] => val2
//            [xyz] => val5
//        )
//
//    [2] => Array
//        (
//            [abc] => val3
//            [xyz] => val6
//        )
//
//)