Help me fix this-Part-2,so I can compile(generics doubt)

[Amit Batra]

  
import java.util.*;
abstract class Animal{
public abstract void checkup();}
 
class Dog extends Animal{
public void checkup(){
System.out.println("Dog Checkup");
}
public String toString(){
return ("I am a Dog");
}
}
class Cat extends Animal{
public void checkup(){
System.out.println("Cat checkup");
}
public String toSring(){
return ("I am a cat");
 
}
}
class Bird extends Animal{
public void checkup(){
System.out.println("Bird checkup");
}
public String toString(){
return ("I am a Bird");
}
}
 
public class AnimalDoctor{
public void checkAnimals(List<Animal> animals){
animals.add(new Dog());
int i=0;
for(Object a:animals)
System.out.println(a.get(i++));
 
//for(Animal a:animals)
//a.checkup();
}
 
public static void main(String[] args){
List<Animal>dogs=new ArrayList<Animal>();
dogs.add(new Dog());
dogs.add(new Dog());
List<Animal>cats=new ArrayList<Animal>();
cats.add(new Cat());
cats.add(new Cat());
List<Animal>birds=new ArrayList<Animal>();
birds.add(new Bird());
 
AnimalDoctor doc=new AnimalDoctor();
doc.checkAnimals(dogs);
doc.checkAnimals(cats);
doc.checkAnimals(birds);
}
}

I want to be able to view all the objects stored in the list. the error Im getting pertains to

 
for(Object a:animals)
System.out.println(a.get(i++));

I know that Object doesnt have a get(), but ive tried all kinds of casts to get it to work. Can anyone help?

[Praveen Babu]

Have you tried the following ?

for(Object a:animals)
System.out.println(a);

[ September 01, 2006: Message edited by: praveen babu ]

[Amit Batra]

Thanks Praveen, it helped alot, but still a part of the output is giving gibberish.
this is what I get
I am a Dog
I am a Dog
I am a Dog
Cat@1f6a7b9
Cat@7d772e
I am a Dog
I am a Bird
I am a Dog

there should be two dogs, two cats, 1 bird and then a dog. Any Suggestions on where Im goofing up?

[Barry Gaunt]

 public String toSring(){
return ("I am a cat");   

Compiler don't check spelling...

[Amit Batra]

What?

[Barry Gaunt]

toSring() ???

[Amit Batra]

whoops . Thanks.

[Dave Reinhardt]

You're getting the toString method inherited from Object because you've mispelled toString as toSring

[bing marquez]

You are adding a new Dog each time checkAnimals is invoked, hence that
output. try removing animals.add(new Dog) from checkAnimals() and you
will get you're desired output of 2 Dogs, 2 Cats and 1 Bird.

[bing marquez]

oops! sorry i didn't see the last dog.

[Barry Gaunt]

Originally posted by Amitabha Batranab:
whoops . Thanks.

Yes, such problems can lose you a lot of time that could be spent otherwise.
Inheritance can sometimes be a real pain.

[Matt Russell]

Straying off-topic from the SCJP, of course, but the @Override annotation can catch problems like this. Bit tedious to type, though.

[Amit Batra]

Straying off-topic from the SCJP, of course, but the @Override annotation can catch problems like this. Bit tedious to type, though.

hey thats kinda cool. I just wish this feature had been on the exam. Just makes me wonder what other useful features I may have missed along the way.