Online PHP editor | output for sa7qN

<?php class LuckyNumbers { public function sumUp(array $digitsOfNumber1, array $digitsOfNumber2): int { $convNum1 = (int) implode($digitsOfNumber1); $convNum2 = (int) implode($digitsOfNumber2); return $convNum1+ $convNum2; throw new \BadFunctionCallException("Implement the function"); } public function isPalindrome(int $number): bool { // Reversing steps:- $numberString = (string) $number; $reverseNumberString = strrev($numberString); $reverseNumber = (int) $reverseNumberString; return $number == $reverseNumber; throw new \BadFunctionCallException("Implement the function"); } public function validate(string $input): string { if ($input <= 0) { echo "Must be a whole number larger than 0"; } if ($input == '') { echo "Required field"; } } } $lucky_numbers = new LuckyNumbers(); $lucky_numbers->validate('123');