<?php

class LuckyNumbers
{
    public function sumUp(array $digitsOfNumber1, array $digitsOfNumber2): int
    {
        return (int) implode('', $digitsOfNumber1) + (int) implode('', $digitsOfNumber2);
    }

    public function isPalindrome(int $number): bool
    {
        return $number == implode('', array_reverse(str_split((string) $number)));
    }

    public function validate(string $input): string
    {
        return match (true) {
            $input == '' => 'Required field',
            (int) $input <= 0 => 'Must be a whole number larger than 0',
            default => '',
        };
    }
}