Object Model

Intro

• The fundamental property of the object model is that computation takes place in and between objects.
• Individual objects are responsible for maintaining a part of systems data and for implementing parts of its functionality.
• Objects therefore combine two fundamental aspects of computer programs - data and processing.

Classes and Objects

• There can be thousands of objects of the same kind with different data.
• So the common structure of a set of objects which represent the same kind of entity is a class.

Visualization

• A running program can be seen as a network or a graph of objects. The objects form the nodes in the graph and the arcs connecting the objects are the links.
• Each object represents data and the structure of the network represents the relationships between this data.
• Objects can be created and destroyed at run time and links can also change. The structure of the graph is very dynamic.

Object Properties

• State: Objects act as containers for data.
• Behaviour: Objects have a number of operations.
• Identity: Every object is distinct from another object.