3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = [ ]; $b = [ ['x', 'y'], ['z', '0'] ]; var_dump([...$a, ...$b]);
Output for 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
array(2) { [0]=> array(2) { [0]=> string(1) "x" [1]=> string(1) "y" } [1]=> array(2) { [0]=> string(1) "z" [1]=> string(1) "0" } }
preferences:
58.92 ms | 406 KiB | 5 Q