OOP Homework 2 --- Due 11/14 before class

Please email your solutions to Anupam Nandan at anupam.nandan@nyu.edu.
Be sure to use "OOP HW1 Solution" as the subject line.

Consider the following Java program:

public class Base {
  public        void m(Object o) { System.out.println("Base.m(Object)"); }
  public static void m(String s) { System.out.println("Base.m(String)"); }
  public        void m(Class c)  { System.out.println("Base.m(Class)");  }
}

public class Derived extends Base {
  public        void m(Object o) { System.out.println("Derived.m(Object)"); }
  public static void m(String s) { System.out.println("Derived.m(String)"); }

  public static void main(String[] args) {
    Base b = new Derived();
    b.m(new Object());
    b.m(new Integer(5));
    b.m("Hello");
    b.m(b.getClass());
  }
}

Assignment 1 (5 Points):

What is the static type of b in Derived.main()?

The static type of b is Base.

Assignment 2 (5 Points):

What is the dynamic type of b in Derived.main()?

The dynamic type of b is Derived because b is assigned only once when
it is initialized and the assigned values is a newly created object of
type Derived.

Assignment 3 (20 Points):

What are the correctly ordered entries in Derived's vtable for our
translator? Please use "classname.methodname(typenames)" notation.
Also, ignore the first entry, which is __isa.

The order of the entries is as follows:

Object.hashCode(Derived)
Object.equals(Derived, Object)
Object.getClass(Derived)
Object.toString(Derived)
Derived.m(Derived, Object)
Base.m(Derived, Class)

Important points: 

- The first parameter of each entry is the implicit __this parameter,
  which is of type Derived because we are describing the vtable of
  class Derived.

- The order of the entries must be compatible with the order of the
  entries in the vtables of the super classes Base and Object. In
  particular, the overriden method Derived.m(Derived, Object) comes
  before the inherited method Base.m(Derived, Class).

- The methods Base.m(String s) respectively Derived.m(String s) are
  not part of the vtable since they are declared static.