Class Fundamentals

The very first object-oriented programming languages, Simula67 [9, 31] and Smalltalk [34], were based on the concepts of class and instance. The majority of the object-oriented languages now in use are based upon these two concepts. Indeed, we can correctly refer to these languages as promoting class-based programming, a style of program construction based upon the idea that the programmer first defines a collection of classes and instantiates those classes when required.