Thread: Polymorphism Question

Hello! This is my first time in this forum. I hope that you guys can help me on this theory question..
It is about polymorphism and I'm not too good at it.

class Food{
	public String show(Food f){
		return("Food Food");
	}
/*	public String show(Fish f){
		return("Food Fish");
	}*/
}
class Fish extends Food{
	public String show(Food f){
		return("Fish Food");
	}
	public String show(Fish f){
		return("Fish fish");
	}
}
class Poly{
	public static void main(String args[]){
		Food fo = new Fish();
		Fish fi = new Fish();
		System.out.print(fo.show(fi));
	}
}

--------------------------------

class Food{
	public String show(Food f){
		return("Food Food");
	}
	public String show(Fish f){
		return("Food Fish");
	}
}
class Fish extends Food{
	public String show(Food f){
		return("Fish Food");
	}
	public String show(Fish f){
		return("Fish fish");
	}
}
class Poly{
	public static void main(String args[]){
		Food fo = new Fish();
		Fish fi = new Fish();
		System.out.print(fo.show(fi));
	}
}

Why is it that code 1 gives me Fish Food
and Code 2 gives me Fish Fish

The only difference with them, is the commented line. THANK YOU!

Hmm, do you by any chance have a link to a good tutorial which involves simple polymorphism and objects passing into them?
I'm just very confused with polymorphism when it comes to,
B1 b = new B();
A1 a1 = new b();

If its just B1 b = new B passing through, i understand how it works. but when A1 is b .. that is where i get lost =(.

I did google for that and went through a few youtube videos already. But none of them have that type of example that i'm looking for sadly..

The type where an object is brought into a class and there should be a method 'calling' the object. Kinda hard to describe it.
But if you look at the code at the first post and espacially to
Food fo = new Fish();
Food = fish...
Almost all examples that i have went through, they do not pass objects into methods..

I have eventually understood it!

In Code 1, there is no show(Fish f) means it will IGNORE ALL subclassess with method carrying (Fish f) in it.
The first line that it reads will thus be in Fish Class, (Food f).

In Code 2, since there is a Fish f in the main class, it will go to
1)Fish class and find if there is a fish f.
If there isn't it will go to 2) Food Class and find if there is a Fish F
If there isn't it will go to 3) Fish Class and find if there is a Food F Since this is the inheritence thing
If there isn't it will go to 4) Food Class and read Food F << There HAS to be this otherwise, compilation error

Correct me if i am wrong please! Thanks!

Anyway, hope you dun mind explaining this very simple type casting to me.
New x = new Newer();
*Assume the two classes are above*
and Newer extends New

so if i put (Newer) x

Does this mean temporarily, x changes to newer ?
Newer x = new Newer ?

Or there is no changes to x ?