3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = [0, 1, 2, 3, 3, 3]; $b = array_unique($a); $b[] = 4; var_dump($b);
Output for 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 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.25, 8.4.1 - 8.4.12
array(5) { [0]=> int(0) [1]=> int(1) [2]=> int(2) [3]=> int(3) [4]=> int(4) }
Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33
array(5) { [0]=> int(0) [1]=> int(1) [2]=> int(2) [3]=> int(3) [6]=> int(4) }

preferences:
140.55 ms | 407 KiB | 5 Q