3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = [1, 2]; $a += [3, 4]; var_dump($a); $a = array_merge($a, [3, 4]); var_dump($a);
Output for 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 - 8.1.31, 8.2.0 - 8.2.27, 8.3.0 - 8.3.16, 8.4.1 - 8.4.3
array(2) { [0]=> int(1) [1]=> int(2) } array(4) { [0]=> int(1) [1]=> int(2) [2]=> int(3) [3]=> int(4) }
preferences:
114.03 ms | 408 KiB | 5 Q