Assign value of nested array as array key

Question

I have a multi dimensional array like this:

[0] => 
 ['batch_id'] => '1'
 ['some_stuff'] => 'values'
 [0] =>
 ['unit_id'] => '12'
 ['some_stuff'] => 'values'
 [1] =>
 ['unit_id'] => '41'
 ['some_stuff'] => 'values'

This comes from an external API, so I have no control over the original formatting of the array.

What would be the preferred (least overhead) way to take all the 'unit_id' and 'batch_id' fields, remove them from the group of values about the item, and assign that value to the item's key?

What I've tried (and works, but I want to find something cleaner):

public function fixArray($batches) {
 $batchfix = array();
 foreach($batches as $batch) {
 $unitfix = $array;
 $batch_temp = $batch;
 array_shift(array_shift($batch_temp)); // Get rid of id details
 foreach($batch_temp as $unit)
 $unittemp = $unit;
 array_shift($unittemp);
 $unitfix[$unit['unit_id']] = $unittemp;
 $batchfix[$batch['batch_id']] = $batch;
 }
 return $batchfix;
}

Any suggestions?

Answer 1

I suppose the result you want to have is this:

 Array
 (
 [1] => Array
 (
 [stuff] => values
 [units] => Array
 (
 [12] => Array
 (
 [stuff] => values
 )
 [41] => Array
 (
 [stuff] => values
 )
 )
 )
 )

In this case you can use the code:

 public function fixArray($originalBatches) {
 $batches = array();
 foreach($originalBatches as $batch) {
 $units = array();
 $batch_id = $batch['batch_id'];
 unset($batch['batch_id']);
 foreach ($batch as $key => $value) {
 if (is_numeric($key) && !empty($value['unit_id'])) {
 $units[$value['unit_id']] = array_slice($value, 1);
 unset($batch[$key]);
 }
 }
 $batches[$batch_id] = array_merge($batch, array('units' => $units));
 }
 return $batches;
 }

Still the use of the 2 foreach is not a very good practice. You can change the code accordingly to use array_walk. This would be much faster.