Question

Given the following array

array(
  0 => array(
    'id' => '54'),
  1 => array(
    'id' => '11'),
  2 => array(
    'id' => '2')
);

Is there a (preferrably built-in) function that re-arranges it to

array(
  0 => '54',
  1 => '11',
  2 => '2'
);

in PHP?

My current way is to iterate over the array and save it to another one, which seems awfully redundant, slow, and inefficient.

$newArray = array();
foreach ($oldArray as $innerArray {
    $newArray[] = $innerArray['id'];
}

Answer 1

How about using array_walk

function array_flatten( &$item ){
    $item = $item['id'];
}

array_walk( $array, 'array_flatten' );