Programming in C++

          Object Oriented Concepts 

Introduction and Evolution of programming languages

The computer technology has evolved at such a fast rate that yesterday's (i.e, some 25 years ago) mainframes are today's personal computers. The software industry is also growing at the same rate proportionally. The operations are becoming more and more complex but, more user friendly, and the
software engineers felt that it was difficult to implement these complex designs using traditional programming languages (i.e., procedural languages or structured programming languages). The programming languages that adopted the procedural and structured programming approach were PASCAL C. COBOL, etc. Generally these languages deal with two important aspects - data and algorithm.

Data is the main substance of the program and the algorithms are the methods that use these programs. They found that these traditional methods of programming was lengthy, expensive, error prone, lacked reusability, difficult to maintain and sometimes even disastrous. Therefore, this lead to the revival of the third generation languages and the result was the fourth generation which further gave birth to the fifth generation languages which was called as Object Oriented Programming System concepts (OOP).

Procedural Programming

The procedural programming focuses on processing of instructions in order to perform a desired computation. Therefore it emphasizes more on doing things i.e. on algorithms. Programming using procedural languages set a threat as the length and complexity of the problem increased. For example, procedural programs make use of branching statements, where the flow of control changes its path according to the result of the test expression. Many programs had these routing and it was difficult to understand and modify them

Structured Programming

The difficulties in procedural programming languages gave a way to the scientists to

develop C language which was better language when compared to the procedural languages. It gave a new idea of programming approach called as Structured Programming approach was a disciplined approach which limited the branching to a small set of well-behaved construction (i.e., if-else statement, for loop, while loop, do while loop and so on). C followed the
top-down principle of programming. The idea of Top-down design is to break a large program into smaller programs, and the smaller programs into still smaller sub-programs further until it can be  implemented for computer solution. However, the structured programming technique reflected the procedural programming method itself, because it lacked the required clarity, reliability and ease of program maintenance as the program length grew in its size. The major drawback of both the procedural and structured programming is that it is very difficult to model the real world using these methods

Object oriented Programming

OOP emphasizes on data unlike the structured programming which emphasizes on program i.e.the ideology here is to unite both the data and the functions that operate on that data into a single unit called as "object".
This can be pasteurized as shown in fig

                            Figure: Objects

Therefore,an object is an identifiable entity with some characteristics and behavior.

Object Oriented Programming (OOP) is a concept that combines both the data and the that operate on that data into a single unit called the object.

Object is an identifiable entity with some characteristics and behavior.

Top-down design is an approach of dividing a problem into sub problems and then dividing the sub problems further into still smaller sub problems until it can be implemented for a computer solution

Bottom up design is the vice versa where solutions to smaller modules are integrated together the solution of the overall program