3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = [ [1, 2, 3], [4, 5, 6], [7, 8, 9], [10, 11, 12], ]; function flip_row_col_array($array) { $out = array(); foreach ($array as $rowkey => $row) { foreach($row as $colkey => $col){ $out[$colkey][$rowkey]=$col; } } return $out; } var_export(flip_row_col_array($array));

preferences:
106.76 ms | 1398 KiB | 5 Q