about interface

[santhosh kumar vk]

hi,


can we use calss in interface, I went to one interview thay asked me how to use class in interface please tell me how to use the class in interface.

[Ninad Kulkarni]

@ santhosh
UseAMeaningfulSubjectLine
Use Java forum for this question.

[David Newton]

I'm not sure what you mean by "using a class in an interface."

[Rob Spoor]

See my comment in http://www.coderanch.com/t/475635/Java-General/java/annotation

[Hiram Nascimento]

Hi Santhosh,

Yes, that's possible. I can give you an example from the Java Collections API.

List<String> myList = new ArrayList<String>();
myList.add("Hello!");

Considering that an ArrayList (class) IS-A (implements) List (interface), you can call its methods by using a List interface reference.

Another example:

interface Player {
    public void play();
}

class IPod implements Player {
    @Override
    public void play() {
         System.out.println("Highwayyyy to Heavennn!!!!");
    }

    public static void main(String[] args) {
         Player p = new IPod();
         p.play();
    }
}

I could either create an IPod reference, but using the Player reference I get the benefits of polymorphism.

Does it make sense for you?

Hiram