Programming Languages questions
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1.

In addition to regular top-level class declarations, Java supports
various flavors of "inner classes:" classes declared within other
classes.  One flavor, called an anonymous inner class, allows a method
to declare and instantiate a class all in one statement:

   public Object getNewObject() {
     final int i = 3;
     Object o = new Object {
       public int getInt() { return i; }
     };
     return o;
   }

(a) How do you suppose the anonymous inner classs mechanism is
    implemented, in terms of the activation record stack, control and
    access links?

(b) Should C++ be extended to support a similar mechanism?  Why or
    why not?

(c) In the example above, removing the "final" from the declaration of
    variable i causes a compiler error.  Why might this be the case?
    Does it change your answer to part (a)?


2.

In Java, collection classes such as queues and stacks all store
references to objects derived from the Object class, allowing any
object to be stored.  In the C++ Standard Library a similar effect is
achieved by instantiating collection classes from class templates.

What are the relative advantages of the two approaches?

3.

Inheritance has been described as just a specialized from of
composition.  In other words, rather than deriving class D from class
B, you could include an instance of class B as a member of D.

What is the main advantage of providing inheritance as part of the
language?

What is the main advantage of composition compared with inheritance?