method with interface return type

[diwakar k.]

It is written in K&B that a method can return interface implementer by citing the following snippet:

public interface Chewable{}
public class Gum implements Chewable{}
 
public class TestChewable
{
    //method with an interface return type
    public chewable getChewable
    {
        return new Gum();//return interface implementer
    }
}

Myquestion is when interfaces are not part of the object's inhertance tree,how could a return type (here an object of class Gum) be returned?? In otherwords is a return type of implementer be returned??

Edited by Corey McGlone: Added CODE Tags
[ August 02, 2004: Message edited by: Corey McGlone ]

[Corey McGlone]

diwakar k.,

Welcome to Javaranch

We'd like you to read the Javaranch Naming Policy and change your publicly displayed name (change it here) to comply with our unique rule. Thank you.

[Corey McGlone]

Originally posted by diwakar k.:
Myquestion is when interfaces are not part of the object's inhertance tree,how could a return type (here an object of class Gum) be returned?? In otherwords is a return type of implementer be returned??

There is no requirement that says that an object to be returned from a method need be in the inheritance tree of the class in which the method is defined. In this case, a new object will be created that implements the interface. That object is then returned. There is no need for that interface to be a part of the inheritance tree of your class - the interface needs only be accessible from this class.