$c = ["a" => ["x" => "X", "y" => "Y"], "b" => ["p" => "P", "q" => "Q"]];
print_r(array_merge(...array_values($c)));
Array
(
[x] => X
[y] => Y
[p] => P
[q] => Q
)
/**
* Function converts multidimentional array to a plain one
*
* @param $arr multidimensional array
*
* @return array
*/
function array_flatten($arr) {
$return = [];
foreach ($arr as $key => $value) {
if (is_array($value)) {
$return = array_merge($return, array_flatten($value));
} else {
$return[] = $value;
}
}
return $return;
}array_merge(...$a);
array_merge([], ...$a);array_merge(...$a);