Here is a quick code snippet for flattening a multi-dimensional array using PHP.
This uses the function array_walk_recursive that applies a function to every element of an array. Using this function we can add the value to a new array and return that instance.
function flatten(array $array) {
$return = array();
array_walk_recursive($array, function($a) use (&$return) { $return[] = $a; });
return $return;
}
print_r(flatten([1, 2, [3], [4, [5, 6], 5, 6], [[7], [8, [9]]], 10, [[[11], 12]]]));
Array
(
[0] => 1
[1] => 2
[2] => 3
[3] => 4
[4] => 5
[5] => 6
[6] => 5
[7] => 6
[8] => 7
[9] => 8
[10] => 9
[11] => 10
[12] => 11
[13] => 12
)