New to Java

Hi all,

Ive got three classes, forming a hierarchy of a super class and 2 sub classes as in the code below

public class Animal {
	public void sound(){
		System.out.println("Animal");
	}
}


public class Dog extends Animal {
	public void sound(){
		System.out.println("Dog");
	}
}

public class Cat extends Animal {

	public void sound(){
		System.out.println("Cat");
	}
}

now in the launch file

Animal animal = new Animal();
animal.sound(); //Animal

Dog dog = new Dog();
dog.sound(); //Dog

Cat cat = new Cat();
cat.sound(); //Cat

these would print the methods shown in the comments, however how would it be possible for a dog to invoke the animal's sound method to display "Animal" instead (typically if i understood right using upcast), and how would it be possible to do the opposite downcast from type animal to invoke sound of dog..

Also would it be possible to convert dog to cat by converting dog to animal then animal to cat ?

Sorry if this post is abit confusing however these class cast (upcast/downcast) are abit confusing me :P

Thanks, i appreciate the help :)