Generics

[Asha Pathik]

Hi,
I've written this code. Could anyone tell me what should I write in place of /* Commented part */ so that it compiles and invoke the getName() method on each of the object stored in aList.

  import java.util.*;
 

public class Generics1
{
public static void main(String[] args)
{
  List<Animal> aList = new ArrayList<Animal>();
  aList.add(new Cat());
  aList.add(new Dog());
  aList.add(new Animal());
  
  System.out.println("Before doing anything " + aList);
  
   AnimalDoctor doc= new AnimalDoctor();
  doc.checkAnimal(aList);
}
}
 

class Animal
{
String name="ANIMAL";
public String getName()
{
return name;
}
}
 
class Cat extends Animal
{
String name="CAT";
public String getName()
{
return name;
}
}
 
class Dog extends Animal
{
String name="DOG";
public String getName()
{
return name;
}
}
 
class AnimalDoctor
{
public void checkAnimal(List<Animal> aList)
{
/*Iterator<Animal> ia = aList.iterator();
while(ia.hasNext());
{
System.out.println(ia.getName());
ia.next();
}
*/  
}
}  

Thanks

[Keith Lynn]

System.out.println(ia.getName());
ia.next();

Notice here that ia is the iterator, it is not an element from the list.

If you change the print statement to

System.out.println(ia.next().getName());

you should get the results you want.

Note also that you have a semicolon where you don't need it in the while loop.

[Asha Pathik]

Thanks Keith. Its working now.