MATLAB Object-Oriented Programming

Some Basic Relationships

This section discusses some of the basic concepts used by MATLAB classes.

Classes

A class is a definition that specifies certain characteristics that all instances of the class

share. These characteristics are determined by the properties, methods, and events that

define the class and the values of attributes that modify the behavior of each of these

class components. Class definitions describe how objects of the class are created and

destroyed, what data the objects contain, and how you can manipulate this data.

Class Hierarchies

It sometimes makes sense to define a new class in terms of existing classes. This

approach enables you to reuse the designs and techniques in a new class that represents

a similar entity. You accomplish this reuse by creating a subclass. A subclass defines

objects that are a subset of those objects defined by the superclass. A subclass is more

specific than its superclass and might add new properties, methods, and events to those

components inherited from the superclass.

Mathematical sets can help illustrate the relationships among classes. In the following

diagram, the set of Positive Integers is a subset of the set of Integers and a subset of

Positives. All three sets are subsets of Reals, which is a subset of All Numbers.

The definition of Positive Integers requires the additional specification that members of

the set be greater than zero. Positive Integers combine the definitions from both Integers

and Positives. The resulting subset is more specific, and therefore more narrowly defined,

than the supersets, but still shares all the characteristics that define the supersets.

3 MATLAB Classes Overview