CIS 400 Assignment 4
                          Fall 1999


     For your next assignment, you will need to complete the 
following lab exercises using Smalltalk. I would prefer 
receiving hardcopy of the relevant Smalltalk screens, but if 
you are not able to this you may write your code and its 
output as a lab report instead.


1. Find the factorial method in the Magnitude subclass
   Integer. Use this as the model for a new recursive
   method which will compute the sum of the numbers 0 
   through N.

2. Write a Smalltalk method that will compute the sum
   of the data values stored in an array.

3. Create a new object subclass called Account which
   contains two instance variables name and balance. 
   Define a method which assigns values to name and 
   balance for new object instances; accessor functions 
   (methods) for retrieving the values of name and balance 
   for Account instances; and methods deposit and withdraw 
   to increment and decrement the value of balance.


     I would prefer you to use SmallTalk/V or Smalltalk
Express for this assignment. You may use any features of the 
Smalltalk language to implement the objects and methods 
required by these exercises. You will need to devise some 
experiments to demonstrate that your code behaves correctly. 
You will need to turn in clearly commented source listings 
of your programs and any relevant computer output (no memo this 
time).


Assigned: 11-24-99
Due date: 12-08-99