What is object oriented programming ?

This question is a little difficult to answer because the computer industry has a fascination for terminologies and catch words. Not long ago words like “artificial intelligence”, ‘’gui” and “net surfing” were used as if they were to offer a path to heavens. The same overuse seems to be happening to the phrase “object oriented” Since it has been proven that object-oriented techniques offer a way to write better programs, every body seems to be slipping the label “object oriented” on their software products.

So it is important for us to understand what is OOP, why do we need it, what does it do that traditional languages like C , Pascal nd Basic don’t and what are the principles behind OOP. This chapter addresses these issues and provides an overview of the features to be discussed in the rest of the book. What we say here will necessarily be general and brief . Don’t worry if you don’t catch everything in this chapter on the first pass; OOP is a complicated beast and learning about it takes time. We will be going over these features again in subsequent chapter . There’s lot of ground to cover here , so let’s get started .

While designing software a guideline that should be followed is ‘The Expression of an algorithm should model the application domain that it support ‘. Or in other words the solution to a problem should resemble the problem that it solves. That is, the observer should be able to recognize that purpose  of the solution without necessarily knowing the problem in advance. For example, when you see a properly designed word processor , you intuitively understand that the problem being solved is one of receiving and manipulating text. Similarly , when you see a properly designed inventory control system , you recognize that its purpose is to maintain a record of stock quantities and locations. 

You recognize those things because the solutions resemble and therefore remind you of the problems that they solve . In a similar sense the purpose of a programming language is to express with algorithms the solution to a data processing problem. The techniques used in that expression determine how  successfully the solution models its problem domain . Earlier , procedural programming was used for expression of a algorithm. Of late it is being replaced by object – oriented programming . To understand why this is so let’s begin by looking at the history of programming methodologies.