Online PHP editor | output for JaKHJ

<?php declare(strict_types = 1); class Engine { public function rev(): void { echo "Reving normal\n"; } } class SportEngine extends Engine { public function revHigh(): void { echo "Reving to the red line!\n"; } } class Car { protected Engine $engine; public function __construct(Engine $engine) { $this->engine = $engine; } public function getEngine(): Engine { return $this->engine; } } class SportsCar extends Car { public function __construct(SportEngine $engine) { $this->engine = $engine; } public function getSportEngine(): SportEngine { return $this->engine; } } $normalCar = new Car(new Engine); $sportScar = new SportsCar(new SportEngine()); $normalCar->getEngine()->rev(); $sportScar->getEngine()->rev(); $sportScar->getSportEngine()->revHigh();