Change key in associative array in PHP

Question

Say I have an array like this:

array(2) {
  [0]=> array(2) {
    ["n"]=> string(4) "john"
    ["l"]=> string(3) "red"
  }
  [1]=> array(2) {
    ["n"]=> string(5) "nicel"
    ["l"]=> string(4) "blue"
  }
}

How would I change the keys of the inside arrays? Say, I want to change "n" for "name" and "l" for "last_name". Taking into account that it can happen than an array doesn't have a particular key.

Answer 1

Using array_walk

array_walk($array, function (& $item) {
   $item['new_key'] = $item['old_key'];
   unset($item['old_key']);
});