Array merge on key of two associative arrays in php?

$output = array();

$arrayAB = array_merge($arrayA, $arrayB);
foreach ( $arrayAB as $value ) {
  $id = $value['id'];
  if ( !isset($output[$id]) ) {
    $output[$id] = array();
  }
  $output[$id] = array_merge($output[$id], $value);
}

var_dump($output);

Optionally if you want to reset output’s keys, just do:

$output = array_values($output);