overriding

[Rich Wright]

This is a question from Jaworski's quiz.
Which of the following are true about method overriding?
A. The overriding and overridden methods must have the same name, argument list, and return type.
B. The overriding method must not limit access more than the overridden method.
C. The overriding method must not throw any exceptions that may not be thrown by the overridden method.
D. The overriding method may not be private.
Answer A, B, C, D. All are true.
I agree with all but choice D.
This code below compiled just fine. So wouldn't answer D be wrong. Maybe I'm overlooking something with the question. Could someone shed some light on this. Thanks.
class A {
private int aMethod(int i){
return 1;
}
}
class B extends A {
private int aMethod(int i){
return 2;
}
}

[paul wheaton]

D is correct.
When you made the method private in your subclass, you made it overload the method instead of override.

[Rich Wright]

What makes aMethod in the subroutine overload aMethod in class A? It has the same return type, argument list and method name.
Overloaded methods must have different arguments.

[Frank Carver]

As Paul said. It's the fact that it's private.
Consider what 'private' means. The 'private' modifier limits the visibility of the method to the defining class. A 'private' method (or member, or inner class) is not visible to derived classes, classes in the same package or completely unrelated classes.
Any other method in class A may call A.aMethod, but no method in class B may call A.aMethod. Class B can't "inherit" A.aMethod, because it is marked as 'private'. Class B simply doesn't know that A has such a method.
In the example, class B defines a method which just happens to have the same signature as a private method in a superclass. But, that private method is completely unknown to class B, so the method in class B can't "override" the superclass method.
If two methods have the same name, but can't be interchanged, they are therfore "overloading" the name. These two methods can't be interchanged, because A.aMethod can only be called by a method of A, and B.aMethod can only be called by a method of B.

[Rich Wright]

Thanks Frank, I understand now.