- Output for 5.6.38, 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 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
- array(5) { [0]=> int(1) [1]=> int(2) [2]=> int(5) [3]=> int(4) [4]=> int(5) }
<?php
$arr = [1, 2, 5, 4, 5];
array_unique($arr);
var_dump($arr);