What is Object Oriented Programming?

Object oriented programming is an approach to programming in which data and code are packaged into a single unit called an 'object'.  An object represents an item, such as a piece of hardware, section of reusable code, transaction, or event.


Aggregation - Object being composed of other objects

Class - Object or set of objects that share a common structure and behavior.  They can have levels in the form of subclasses and superclasses

Encapsulation - capability of an object to have data (properties) and functionality (methods) available to the user without the user having to understand the implementation within the object.  Often called the closed box or black box concept.

Event - entire process of trigger sending a message that causes an operation to occur.

Event diagram - shows relationships among events and operations

Event driven - programs constructed in a manner so that the system does nothing unless a trigger causes an event to occur

Generalization hierarchy - Shows the relationships among the classes

Implementation - General category of object types

Information hiding - process of making the implementation and programming details transparent to the user

Inheritance - ability to use a class, along with it's functions and data, to create a subclass, thus saving time and coding.

Instance - Unique object or specific occurrence of a class of objects

Message - a message activates the code to perform one of the operations.  A message consists of the name of the object that is the recipient of the message, and the name of the operation to be performed.

Operation - a service.  An activity that reads or manipulates the data of an object.

Polymorphism - allows an instruction to be given to an object using a generalized rather than specific, detailed command.

Transparent - action that takes place without any visible effect other than the desired output.

Trigger - impetus that causes a message to be sent.  A trigger may come from another object or an external user.

UML - Unified Modeling Language - standardized model for object oriented design to depict or describe concepts graphically