3v4l.org

run code in 300+ PHP versions simultaneously
<?php $arr1 = array( 0 => array(1, 2), 1 => array(5, 6) ); $arr2 = array( 0 => array(2, 3), 1 => array(6, 7) ); var_export( array_map( fn(...$rows) => array_values(array_unique(array_merge(...$rows))), $arr1, $arr2 ) );

preferences:
27.74 ms | 408 KiB | 5 Q