In-Class Exercise 5-2 Definitions

Class: A class is a general template that we use to create specific instances, or objects, in the problem domain.

Class Types

Concrete Class: Specific and not an abstract/generalized class. Used to create objects. For example, a concrete class would be “Doctor,” “Patient,” “Receptionist,” etc.

vs.

Abstract Class: Does not actually exist in the real world, as it is simply a useful abstraction. For example, an abstract class is a generalization of Concrete Classes, such as “Doctor,” “Patient,” and “Receptionist” into an abstract class called “Person.”

Domain Class: Represents objects in the problem domain. That is, they are used to represent objects that meet the Functional Requirements rather than the Nonfunctional Requirements.

Functional Requirement: Relates directly to a process a system must perform or information it needs to contain. For example, requirements stating that a system must have the ability to search for available inventory or to report actual and budgeted expenses are Functional Requirements.

vs.

Nonfunctional Requirement: Behavioral properties that the system must have, such as performance and usability. The ability to access the system using a Web browser is considered a Nonfunctional Requirement.