Online PHP editor | refs for DdODR

<?php $a = [ 'a' => [ 'a1' => 'a1', 'a2' => 'a2', 'a3' => 'a3', ], 'b' => [ 'b1' => 'b1', 'b2' => 'b2', 'b3' => 'b3', ], ]; $it = new RecursiveIteratorIterator(new ArrayIterator($a)); $b = []; foreach ($it as $key => $value) { $b[$key] = $value; } var_dump($b);