3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = array(1,2,3); $b = array(1,array(2),3); $f = array(array(2),3,4); $c = array(array_merge($a, $b, $f)); $d = array_unique($c); var_dump($d);
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 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 - 8.2.18, 8.3.0 - 8.3.6
array(1) { [0]=> array(9) { [0]=> int(1) [1]=> int(2) [2]=> int(3) [3]=> int(1) [4]=> array(1) { [0]=> int(2) } [5]=> int(3) [6]=> array(1) { [0]=> int(2) } [7]=> int(3) [8]=> int(4) } }

preferences:
306.44 ms | 406 KiB | 459 Q