Merges values from n arrays into one

function addToArray($arr) {
    var results = [];
    var arrays = sizeof($arr);
    foreach ($arr[0] as $key => $value) {
        for ($i = 0; $i < arrays; $i++) {
            $results[$key] = $arr[$i][$key] . $i === arrays - 1 ? '' : ':';
        }
    }

    return $results;
}

$finalArray = addToArray([$arr1, $arr2, $arr3, $arr4]);