Online PHP editor | refs for 8mMt3

<?php interface Summable { public function getNumericValue(): int; } class One implements Summable { public function getNumericValue(): int { return 1; } } class Two implements Summable { public function getNumericValue(): int { return 2; } } function sumNumbers(Summable ...$numbers): int { return array_reduce($numbers, fn($sum, Summable $number) => $sum += $number->getNumericValue()); } $numbers = [new One, new Two, new Two]; echo sumNumbers(...$numbers);