3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = ['A[1]', 'B[2]', 'C[2]', 'D[2]']; $b = ['B[3]', 'C[4]', 'E[4]', 'F[2]', 'G[2]']; $result = []; foreach ($a as $v) { $result[strtok($v, '[')] = $v; } foreach ($b as $v) { $result[strtok($v, '[')] = $v; } var_export(array_values($result));
Output for 7.4.0 - 7.4.33, 8.0.1 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.26, 8.4.1 - 8.4.13
array ( 0 => 'A[1]', 1 => 'B[3]', 2 => 'C[4]', 3 => 'D[2]', 4 => 'E[4]', 5 => 'F[2]', 6 => 'G[2]', )

preferences:
84.88 ms | 407 KiB | 5 Q