3v4l.org

run code in 300+ PHP versions simultaneously
<?php $arr = array(1, 2, 3, 4); $arr2 = array(4, 5, 6, 7); $test = array_merge($arr, $arr2); print_r($test);
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, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.10, 7.2.0 - 7.2.33, 7.3.12 - 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 ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 [4] => 4 [5] => 5 [6] => 6 [7] => 7 )

preferences:
232.83 ms | 405 KiB | 309 Q