needs explanation

[Venkat Ramsimha]

class Animal
{
}
class Horse extends Animal
{
}
public class UseAnimals
{
public void doStuff(Animal a)
{
System.out.println("In the Animal version");
}
public void doStuff(Horse h)
{
System.out.println("In the Horse version");
}
public static void main (String [] args)
{
UseAnimals ua = new UseAnimals();
Animal animalObj = new Animal();
Horse horseObj = new Horse();
ua.doStuff(animalObj);
ua.doStuff(horseObj);


Animal animalRefToHorse = new Horse();
ua.doStuff(animalRefToHorse);
}
}

OUTPUT:
In the Animal version
In the Horse version
In the Animal version

Hi All,
can anybody explain me how the output is generated for the above program?

[deepu Bhalotia]

class Animal
{
}
class Horse extends Animal
{
}
public class UseAnimals
{
public void doStuff(Animal a)
{
System.out.println("In the Animal version");
}
public void doStuff(Horse h)
{
System.out.println("In the Horse version");
}
public static void main (String [] args)
{
UseAnimals ua = new UseAnimals();
Animal animalObj = new Animal();
Horse horseObj = new Horse();
ua.doStuff(animalObj);
ua.doStuff(horseObj);


Animal animalRefToHorse = new Horse();
ua.doStuff(animalRefToHorse);
}
}

OUTPUT:
In the Animal version
In the Horse version
In the Animal version

Hi,
This is the Perfect Example of Overloading.. In Overloading the Compiler Check for the Reference type.


Animal animalRefToHorse = new Horse();
ua.doStuff(animalRefToHorse);

Here the Reference is of Animal. So the doStuff method that takes animal object as a Arguments gets executed...

Animal animalObj = new Animal();

Here the Reference is of Animal. So Animal version....

Horse horseObj = new Horse();
Here the Reference is of Horse. So Horse version gets executed...


Hope this will clarify your doubt...

Deepak
[ May 10, 2005: Message edited by: deepu Bhalotia ]

[Venkat Ramsimha]

thanks
deepak.iam clear now

[Ashok Kumar]

HI Venkat,

Nice to see a lot of questions from you.It covers most of the concepts.It seems like anyone preparing for SCJP has to just follow your threads and all his doubts will be cleared.

[Venkat Ramsimha]

thanks ashok

[Jkarthi keyan]

There is also another point to be noted in this code i.e the base class reference is given to the subclass object.

Regards
Jkarthi