java/w6/TestAnimal.java

public class TestAnimal {

    public static void animalSound(Animal a) {
        a.makeSound();
    }


    public static void trySwim(Animal a) {
        if (a instanceof Swimmable) {
            Swimmable s = (Swimmable) a;
            s.swim();
        } else {
            System.out.println("❌ 这只动物不会游泳！");
        }
    }

    public static void main(String[] args) {

        Animal dog = new Dog();
        Animal cat = new Cat();

        System.out.println("=== 1. 多态调用叫声（抽象类多态） ===");
        animalSound(dog);
        animalSound(cat);

        System.out.println("\n=== 2. 多态调用游泳（接口多态） ===");
        trySwim(dog);
        trySwim(cat);


        System.out.println("\n=== 3. 接口引用直接调用 ===");
        Swimmable swimmer = new Dog();
        swimmer.swim();
    }
}