How to merge subarray in PHP most easily?

Question

$arr[] = array(\'A\',\'B\');
$arr[] = array(\'C\',\'B\');
...

I need to get the merged result of all sub array of $arr .

And f

Answer 1

This answer is based on Felix Kling post. It's more accurate version with fixing "non array" sub-elements.

$res = array_reduce($res, function(&$res, $v) {
                            return array_merge($res, (array) $v);
                        }, array());