3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = [ 'a' => [ 'a1' => 'a1', 'a2' => 'a2', 'a3' => 'a3', ], 'b' => [ 'b1' => 'b1', 'b2' => 'b2', 'b3' => 'b3', ], ]; $it = new RecursiveIteratorIterator(new RecursiveArrayIterator($a)); $b = []; foreach ($it as $key => $value) { $b[$key] = $value; } var_dump($b);
Output for 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.19, 8.3.0 - 8.3.7
array(6) { ["a1"]=> string(2) "a1" ["a2"]=> string(2) "a2" ["a3"]=> string(2) "a3" ["b1"]=> string(2) "b1" ["b2"]=> string(2) "b2" ["b3"]=> string(2) "b3" }
preferences:
234.59 ms | 404 KiB | 378 Q