3v4l.org

run code in 500+ PHP versions simultaneously
<?php $option1 = ['filter' => ['foo', 'bar']]; $option2 = ['filter' => ['baz']]; var_dump(array_merge($option1, $option2));
Output for 8.0.1 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.31, 8.3.0 - 8.3.31, 8.4.1 - 8.4.22, 8.5.0 - 8.5.7
array(1) { ["filter"]=> array(1) { [0]=> string(3) "baz" } }

preferences:
65.71 ms | 1138 KiB | 4 Q