You must write and test classes to get full credit in Project 2

You should tackle one of the programming exercises at the end of chapter 10 or chapter 11. List of options below. Detailed list below with comments.

Due at start of class 8

UML Please

Please include a rough diagramn of the classes in your code. Scribble them in a blank spaces in the code. Or on the reverse side of the printout.

Use the Unified Modelling language.

A very rough UML scetch is an easy and fast way to start thinking about any new class you are about to code. Engineers have a tradition of using napkins for this kind of design.

Remember that when you are stuck writing or debugging code, it helps to shift to pictures and diagrams. Rough UML can help.

Main Program should test classes

When asked to develop one or more classes you should also develop and hand in a main program that tests the classes. A test of a class is called a "Unit Test". The main program is a good place for a rough picture of all classes tested and all tested connections between them.

I find that wrting the tests first helps me understnad the classes I have to write better. I use

 	#include <cassert>

so that the main program can test that an operation/method/function works

 		assert( object.operation(data) == expected_result);

I'll try to demo this in a lecture/discussion.

Common Syntax errors in C++ classes

• Forgetting the ';' after the last '}'.
• Trying to initialize an attribute in its declaration. Do it in constructors.
• Forgetting Scope rules.

Common Semantic errors in C++ classes

• Not modeling the real world.
• Putting data about Y inside class called X. Putting operation in the wrong class.
• Trying to use a private member outside its class.
• Putting something in a class that belongs in the main program.
• Not enough constructors...

Good style in C++ Classes

• Class names start with a CAPITAL LETTER.
• Attribute and function names start with a lower case letter.
• Attributes are nearly always private and function/operation public.
• Aim for many tiny operations rather than a few big ones.
• Don't put all the intelligence and control inside one object.

Working faster

Make some blank .h and .cpp files for a Blank class and Operations.

10.8 Savings Account class

10.9 IntegerSet class

I would start with the driver program and add one feature at a time.

11.15 RationalNumber class

11.17 Polynomial class

. . . . . . . . . ( end of section Project 2 Classes) <<Contents | End>>

Abbreviations