Online PHP editor | refs for GQHTE

<?php $info = [ ['car' => 'Audi', 'previous_car' => 'BMW'], ['car' => 'Audi', 'previous_car' => 'Seat'], ['car' => 'Audi', 'previous_car' => 'BMW'], ['car' => 'BMW', 'previous_car' => 'BMW'], ['car' => 'Ford', 'previous_car' => 'Seat'], ]; $result = []; foreach ($info as $row) { foreach ($row as $k => $v) { $result[$k][$v] = ($result[$k][$v] ?? 0) + 1; } } var_export($result);