Fundamentals of Object- Oriented Programming

INTRODUCTION

One characteristic that is constant in the software industry today is the "change". Change is one of the most critical aspects of software development and management. New tools and new approaches are announced almost every day. The impact of these developments is often very extensive and raises a number of issues that must be addressed by the software engineers. Most important among them are maintainability, reusability, portability, security, integrity, and user friendliness of software products.

To build today's complex software it is just not enough to put together a sequence of programming statements and sets of procedures and modules. We need to use sound construction techniques and program structures that are easy to comprehend, implement and modify in a wide variety of situations.

Since the invention of the computer, many programming approaches have been tried. These include techniques such as modular programming, top-down programming, bottom-up programming and structured programming. The primary motivation in each case has been the concern to handle the increasing complexity of programs that are reliable and maintainable. These techniques became popular among programmers over the last two decades.

With the advent of languages such as C, structured programming became very popular and was the paradigm of the 1980s. Structured programming proved to be a powerful tool that enabled programmers to write moderately complex programs fairly easily. However, as the programs grew larger, even the structured approach failed to show the desired results in terms of bug-free, easy-to-maintain, and reusable programs.

Object-Oriented Programming (OOP) is an approach to program organization and development, which attempts to eliminate some of the pitfalls of conventional programming methods by incorporating the best of structured programming features with several new concepts. It is a new way of organizing and developing programs and has nothing to do with any particular language. However, not all languages are suitable to implement the OOP concepts easily. Languages that support OOP features include Smalltalk, Objective C, C + + , Ada and Object Pascal. C+ +, an extension of C language, is the most popular 00P language today C++ is basically a procedural language with object-oriented extension. The latest one added to this list is Java, a pure object-oriented language.