3v4l.org

run code in 300+ PHP versions simultaneously
<?php $x = [1, 2, 3, 3]; $z = array_unique($x); var_dump($z);
Output for 7.0.0 - 7.0.25, 7.1.0 - 7.1.20, 7.2.6 - 7.2.33, 7.3.16 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
array(3) { [0]=> int(1) [1]=> int(2) [2]=> int(3) }

preferences:
169.91 ms | 403 KiB | 176 Q