CS242 Section Nov. 14, 2002

Outline


Object Oriented Programming Concepts

There are a few key concepts that you ought to know. In particular, think about each of the languages we study and how they handle each of these concepts. Inheritance does not necessarily mean new object is a subtype of the original one. Subtyping is a relation on interfaces, inheritance is a relation on implementations.

Simula

The first object-oriented language. We went over the drawing on pg. 306 of the text and talked about why everything was set up the way it was.

Smalltalk

A user friendly programming language with a table-based editor for generating objects. There is lots of terminology associated with Smalltalk, found on pg 312 of the text. Remember that everything in Smalltalk is an object.

We went over the runtime representation of the ColoredPoint object found on page 317 of the text. We also looked at the diagram shown on pg 325 showing subtyping and inheritance relations.

Midterm Questions

We answered a couple of specific concerns people had on the midterm.