3v4l.org

run code in 500+ PHP versions simultaneously
<?php $arr = [ 0 => [ 0 => 123, 1 => 108, 2 => 58, 3 => 23, ], 1 => [ 0 => 93, 1 => 94, 2 => 95, 3 => 172, 4 => 30, ], 2 => [ 0 => 109, 1 => 81, 2 => 79, 3 => 155, ], ]; $result = array_merge(...$arr); print_r($result);
Output for 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.6
Array ( [0] => 123 [1] => 108 [2] => 58 [3] => 23 [4] => 93 [5] => 94 [6] => 95 [7] => 172 [8] => 30 [9] => 109 [10] => 81 [11] => 79 [12] => 155 )
preferences:
118.36 ms | 1671 KiB | 5 Q