3v4l.org

run code in 300+ PHP versions simultaneously
<?php $default = [ 'value' => '', ]; $input = [ 'value' => null, ]; var_dump(array_merge($default, $input));
Output for 7.4.0 - 7.4.33, 8.0.1 - 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(1) { ["value"]=> NULL }
preferences:
96.8 ms | 406 KiB | 5 Q