public class TestInterfaces
{
    public void walkingAnimals()
    {
        Walkable[] w = new Walkable[5];
        w[0] = new Person("Jack");
        w[1] = new Person("Manfred");
        w[2] = new Duck("Donald");
        w[3] = new Person("John");
        w[4] = new Duck("Dagobert");
        
        for (int i=0; i<w.length; i++)
            w[i].walk();   
    }

    public void swimmingAnimals()
    {
        Swimmable[] s = new Swimmable[5];
        s[0] = new Fish("Nemo");
        s[1] = new Fish("Wanda");
        s[2] = new Duck("Donald");
        s[3] = new Fish("Flipp");
        s[4] = new Duck("Dagobert");

        for (int i=0; i<s.length; i++)
            s[i].swim();
    }

    public static void main(String[] args)
    {
        TestInterfaces test = new TestInterfaces();
        test.walkingAnimals();
        test.swimmingAnimals();
    }
}