Online PHP editor | refs for Zl5iI

<?php $a1 = [ ['target_id' => 123], ['target_id' => 234], ['target_id' => 345], ]; $a2 = [ ['target_id' => 124, 'type' => 'node'], ['target_id' => 234, 'type' => 'node'], ['target_id' => 345, 'type' => 'node'], ]; var_dump(array_udiff($a1, $a2, function ($a, $b) { return ($a['target_id'] == $b['target_id']); }));