Online PHP editor | refs for SB4un

<?php $ar1 = array( (object) array('id' => '1505', 'category' => 'blue'), (object) array('id' => '1805', 'category' => 'red') ); $ar2 = array( '1777' => (object) array('id' => '1505', 'category' => 'yellow'), '1877' => (object) array('id' => '1507', 'category' => 'blue'), ); $ids = array_column($ar1, 'id'); $ar3 = array_merge_recursive($ar1, array_filter($ar2, function($x) use ($ids) { return !in_array($x->id, $ids); })); print_r($ar3);