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<?php $a1 = array('red'); $a2 = array('red', 'blue'); $diff = array_udiff($a1, $a2, function($a, $b) { if($a === $b) { return 0; } else { return -1; } }); var_dump($diff);
Output for 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.19, 8.3.0 - 8.3.7
array(0) { }
Output for 5.5.0 - 5.5.38, 5.6.0 - 5.6.40
array(1) { [0]=> string(3) "red" }
preferences:
231.9 ms | 402 KiB | 332 Q