Online PHP editor | output for aAa32

<?php $postArray = array ( 0 => array ( 'id' => 1, 'post' => 'hello', 'userId' => 1, 'fileName' => 'hey.jpg', 'time' => 0, ), 1 => array ( 'id' => 1, 'post' => 'hello', 'userId' => 1, 'fileName' => 'test.png', 'time' => 53252354, ), 2 => array ( 'id' => 2, 'post' => 'world', 'userId' => 1, 'fileName' => 'asd.png', 'time' => 0, ), 3 => array ( 'id' => 4, 'post' => 'test', 'userId' => 1, 'fileName' => 'asd2.png', 'time' => 0, ), 4 => array ( 'id' => 3, 'post' => 'ouch', 'userId' => 2, 'fileName' => NULL, 'time' => NULL, ), ); foreach ($postArray as $post) { $fixed_part = array('id' => $post['id'], 'post' => $post['post'], 'userId' => $post['userId']); $key = serialize($fixed_part); if (!isset($out[$key])) $out[$key] = $fixed_part; $out[$key]['attachments'][] = array('fileName' => $post['fileName'], 'time' => $post['time']); } $out = array_values($out); echo json_encode($out, JSON_PRETTY_PRINT);