3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = array('code' => 500, 'am' => 600, 'cc' => 560); $b = array('am' => 40, 'dd' => 100); var_dump(array_merge($a, $b));
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, 5.5.0 - 5.5.38, 5.6.0 - 5.6.25, 7.0.0 - 7.0.20, 7.1.0 - 7.1.10, 7.2.29 - 7.2.33, 7.3.12 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
array(4) { ["code"]=> int(500) ["am"]=> int(40) ["cc"]=> int(560) ["dd"]=> int(100) }

preferences:
243.95 ms | 406 KiB | 352 Q