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

$merged_array = array_reduce($serp_res, 'array_merge', array()); with added quotas,'array_merge', worked for me.