CSC/ECE 517 Fall 2011/ch1 1e ap

Introduction to Object Oriented Design

Introduction to Object Oriented Programming

Object-oriented programming (OOP) is a programming language model organized around "objects" rather than "actions" and data rather than logic. It uses "objects" - data structures consisting of data fields and methods together with their interactions – to design applications and computer programs.

Object-oriented programming takes the view that what we really care about are the objects we want to manipulate rather than the logic required to manipulate them. Examples of objects range from human beings (described by name, address, and so forth) to buildings and floors (whose properties can be described and managed) down to the little widgets on your computer desktop (such as buttons and scroll bars).

Object-oriented programming is a method of programming based on a hierarchy of classes, and well-defined and cooperating objects.

• Classes

The class is the fundamental object-oriented unit. It is a structure that defines the data and the methods to work on that data. Classes define a set of objects that share a common structure and behavior. When you write programs in the Java language, all program data is wrapped in a class.All objects are created from classes, so it important to understand the structure of a class. In fact, it is the design of classes that has fueled the development of various Object Oriented languages.Object is an instance of a class.

• Objects

An "Object" is binding together of data and behavior, and Object Oriented programming, is the use of objects while solving the problem. What makes an "object" unique is the formal and explicit combination of these smaller pieces' behavior with its' data into a single entity.