3v4l.org

run code in 300+ PHP versions simultaneously
<?php $items = array( array( array("Color" => "Blue"), array("Size" => "S") ), array( array("Color" => "Blue"), array("Size" => "M") ) ); $new_items = array_map(function ($item) { $seed = array(); return array_reduce($item, function ($seed, $key_values) { return array_map(function ($value) { $seed[] = $value; }, $key_values); return $seed; }, array()); }, $items); var_dump($new_items);

preferences:
26.09 ms | 402 KiB | 5 Q