Does the java compiler internally create constructors for interfaces?

Question

Below is a simple program that I have:

interface X {}

public class Y implements X {
    public static void main(String[] args) {
        X x = new Y();
    }
}

Now, as far as I know, the variable x would be able to hold an object type of Y if an is-a relationship existed between Y and X. That is to say that class Y is a type of interface X.

But we know that interfaces cannot be instantiated and cannot have constructors. Does the compiler then create a constructor for the interface in the .class file ?

score 5 · Accepted Answer · answered Mar 20 '18 at 06:15

5

But we know that interfaces cannot be instantiated and cannot have constructors. Does the compiler then create a constructor for the interface in the .class file ?

No.

You are not instantiating X here, you are instantiating object Y and you are assigning it to X, because Y is of type X.

The paradigm is called as programming to interfaces.

answered Mar 20 '18 at 06:15

Suresh Atta

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Thanks. So, does Y implementing X imply that Y is a type of X? If yes, that would mean that, interfaces are just a different form of abstract classes. – Moses Mar 20 '18 at 06:17
1

@Moses True. Your understanding is correct. – Suresh Atta Mar 20 '18 at 06:19

Does the java compiler internally create constructors for interfaces?

1 Answers1