Pass array as individual items in another array

In Drupal 8, you can use NestedArray::unsetValue() to unset a value is nested arrays. You can also use NestedArray::getValue() and NestedArray::setValue() to get and set value from nested arrays using a array of keys ($parents).

Drupal 7 only have drupal_array_get_nested_value() and drupal_array_set_nested_value(). But no drupal_array_unset_nested_value(). It can easily be ported from Drupal 8:

/**
 * Unsets a value in a nested array with variable depth.
 *
 * This helper function should be used when the depth of the array element you
 * are changing may vary (that is, the number of parent keys is variable). It
 * is primarily used for form structures and renderable arrays.
 *
 * @param array $array
 *   A reference to the array to modify.
 * @param array $parents
 *   An array of parent keys, starting with the outermost key and including
 *   the key to be unset.
 * @param bool $key_existed
 *   (optional) If given, an already defined variable that is altered by
 *   reference.
 *
 * Port of NestedArray::unsetValue() from Drupal 8
 *
 * @see drupal_array_get_nested_value()
 * @see drupal_array_set_nested_value()
 */
function drupal_array_unset_nested_value(array &$array, array $parents, &$key_existed = NULL) {
  $unset_key = array_pop($parents);
  $ref = &drupal_array_get_nested_value($array, $parents, $key_existed);
  if ($key_existed && is_array($ref) && array_key_exists($unset_key, $ref)) {
    $key_existed = TRUE;
    unset($ref[$unset_key]);
  }
  else {
    $key_existed = FALSE;
  }
}