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1 MODERN PROGRAMMING LANGUAGE TECHNIQUES Dilawar 1 1 Ch. Mani Ram Godara Govt. College For Women, Bhodia Khera, Fatehabad, INDIA dilawarfatehabad@gmail.com Abstract--This paper focus on introduction of computer langauages, journey from low level language i.e. from machine language to high level language is discussed. Introduction to basic features of object oriented languages(oops) is also given. 1. INTRODUCTION TO PROGRAMMING LANGUGE Language is way of communication with others. Similarly Computer Language is way of communication with computer. There are a number of languages. Computer languages are of two types 1. Low Level Language 2. High Level Language There are two categories of low level languages namely a. Machine (Binary Language) b. Assembly Language. Computer is an electronic device, it can understand only the language of 0 and 1 i.e. binary language, which is also termed as machine language. The programming in binary language is very difficult. Only professional could program using binary language. Then the need for more simple language arose. The assembly language which was invented to fulfill this need uses shortcuts, for example ADD for addition, SUB for subtraction, MUL for multiplication and DIV for division and so on. Problem with assembly language is that it can t be understood by computer directly. A program written in Assembly language need to be converted into binary language so that it can be understood by computer. We have to convert assembly language program into binary language by using assembler. After sometime high level languages were invented. High level languages are very easy to understand. These are combination of english words and mathematical expressions. The problem with high level language is that computer can t understand this language directly. We have to convert high level language into binary language. This is done though either compiler or interpreter.. II. DIFFERENCE BETWEEN INTERPRETER AND COMPILER Both are language translators converting high level language program to binary language program, but difference is that compiler takes complete program at a time and convert it into machine language but interpreter taken one line at time convert it into binary, then take the next and so on. No Compiler Compiler Takes Entire program as input Intermediate Object Code is Generated Conditional Control Statements are Executes faster Interpreter Interpreter Takes Single instruction as input. No Intermediate Object Code is Generated Conditional Control Statements are Executes slower Memory Requirement : More Memory Requirement is Less (Since Object Code is Generated) Program need not be compiled every time Every time higher level program is converted into lower level program Errors are displayed Errors are displayed for every after entire program instruction interpreted (if any) is checked Example : C Compiler Example : VISUAL BASIC Fig 1: Computer Language III. PROCEDURAL PROGRAMMING In procedural language the problem to be solved in thought to have a solution in a form of a sequence of steps. Programming languages like pascal, cobol are procedural languages. A group of instructions known as functions are frequently used in procedural programming. Top down approach is being followed in procedural language. A large problem is divided into smaller problems. ISSN Page 43

2 IV. INTRODUCTION TO OBJECT ORIENTED LANGUE C++ programming language developed by Bejarne Stroustrup in early 1980s. His aim was to create a language having features of both simula67 and C language. In c language is not able to model real life problem. If fact c with classes was C++, the name was given by Rick Mascitti. The first version was released in 1985 and 2 nd version was release in With C++ the real life problems can be implemented. Large real world complex applications are solved using OOPs. Programming approaches has seen a lot of milestones just similar to computer hardware. In early days the machine language was being used which was really very difficult and it s successor Assembly language was too very difficult so the procedural programming languages were invented making it possible to write large programs containing hundreds lines of code. Structured programming was invented and then after this Object Oriented Programming was invented. Object oriented programming divide the problem into smaller objects and builds data and functions around these. The data of an object can be accessed only by the function associated with that object In OOPs program is divided into objects and not in functions. It pays attention on what to do and not how to solve a given problem. It represents real world modeling, the problem is solved using this approach is close to reality. Concept of message passing is used for communication between different objects. Bottom-up approach is being followed. Maintenance as well as modification of a program is easy. IV. IN DEPTH OOPS Object Oriented Programming consists of following main features 4.1Class and Object A class is a blueprint of an object. You can think of a class as a concept, and the object is the embodiment of that concept. You need to have a class before you can create an object. So, let's say you want to use a person in your program. You want to be able to describe the person and have the person do something. A class called 'person' would provide a blueprint for what a person looks like and what a person can do. To actually use a person in your program you need to create an object. You use the person class to create an object of the type 'person.' Now you can describe this person and have it do something. Classes are very useful in programming. Consider the example of where you don't want to use just one person but 100 people. Rather than describing each one in detail from scratch, you can use the same person class to create 100 objects of the type 'person.' You still have to give each one a name and other properties, but the basic structure of what a person looks like is the same. For example class demo int privar; void prifun() public: int pubvar; voice pubfun() void main demo object1; //defining object of type class Objects, run time entity represents a person, a place or a thing of our world. In fact the function represent action of object. The basic idea in OOP is to think of objects and communication between these objects. Every object contain data and code to manipulate the data. Message passing mechanism for interobject communication. class employee int basic, hra, netpay; public : void getdetail() cout<< Enter your basic pay ; cin>>basic; cout<< Enter HRA ; cin>>hra; void tellnetpay() netpay=basic+hra; cout<< The Net Pay is <<netpay; ISSN Page 44

3 void main() employee zenia; zenia.getdetail(); zenia.tellnetpay(); dilawar.getdetail(); dilawar.tellnetpay(); return length * breadth * height; double length; // Length of a box double breadth; // Breadth of a box double height; // Height of a box The variables length, breadth, and height are private. This means that they can be accessed only by other members of the Box class, and not by any other part of your program. This is one way encapsulation is achieved. To make parts of a class public (i.e., accessible to other parts of your program), you must declare them after the public keyword. All variables or functions defined after the public specifier are accessible by all other functions in your program. Making one class a friend of another exposes the implementation details and reduces encapsulation. The ideal is to keep as many of the details of each class hidden from all other classes as possible. Fig 2 : Object Oriented Approach In the example given above, name of class is employee, it contains various features which are divided into two categories named private and public. These features are in the form or variables and functions. Here basic, hra, netpay are variables and getdetail,tellnetpay are functions. 4.2 Encapsulation Encapsulation is an Object Oriented Programming concept that binds together the data and functions that manipulate the data, and that keeps both safe from outside interference and misuse. Data encapsulation led to the important OOP concept of data hiding. Data encapsulation is a mechanism of bundling the data, and the functions that use them and data abstraction is a mechanism of exposing only the interfaces and hiding the implementation details from the user. C++ supports the properties of encapsulation and data hiding through the creation of user-defined types, called classes. We already have studied that a class can contain private, protected and public members. By default, all items defined in a class are private. For example: class Box public: double getvolume(void) 4.3 Abstraction Abstraction (from the Latin abs, meaning away from and trahere, meaning to draw) is the process of taking away or removing characteristics from something in order to reduce it to a set of essential characteristics. In object-oriented programming, abstraction is one of three central principles (along with encapsulation and inheritance). Through the process of abstraction, a programmer hides all but the relevant data about an object in order to reduce complexity and increase efficiency. In the same way that abstraction sometimes works in art, the object that remains is a representation of the original, with unwanted detail omitted. The resulting object itself can be referred to as an abstraction, meaning a named entity made up of selected attributes and behavior specific to a particular usage of the originating entity. Abstraction is related to both encapsulation and data hiding. In the process of abstraction, the programmer tries to ensure that the entity is named in a manner that will make sense and that it will have all the relevant aspects included and none of the extraneous ones. A real-world analogy of abstraction might work like this: You (the object) are arranging to meet a blind date and are deciding what to tell them so that they can recognize you in the restaurant. You decide to include the information about where you will be located, your height, hair color, and the color of your jacket. This is all data that will help the procedure (your date finding you) work smoothly. You should include all that information. On the ISSN Page 45

4 other hand, there are a lot of bits of information about you that aren't relevant to this situation: your social security number, your admiration for obscure films, and what you took to "show and tell" in fifth grade are all irrelevant to this particular situation because they won't help your date find you. However, since entities may have any number of abstractions, you may get to use them in another procedure in the future. 4.4 Polymorphism Below is a real-life example of polymorphism. For the example program Polymorphism means to process objects differently based on their data type. In other words it means, one method with multiple implementation, for a certain class of action. And which implementation to be used is decided at runtime depending upon the situation (i.e., data type of the object) This can be implemented by designing a generic interface, which provides generic methods for a certain class of action and there can be multiple classes, which provides the implementation of these generic methods. Lets us look at same example of a car. A car have a gear transmission system. It has four front gears and one backward gear. When the engine is accelerated then depending upon which gear is engaged different amount power and movement is delivered to the car. Polymorphism could be static and dynamic both. Overloading is static polymorphism while, overriding is dynamic polymorphism. Overloading in simple words means two methods having same method name but takes different input parameters. This called static because, which method to be invoked will be decided at the time of compilation Overriding means a derived class is implementing a method of its super class. 4.5 Message Passing Concept of message passing is used for inter object communication. From the programmer point of view message passing provides an easy way of modeling real world problems on the computer. Message to an object is treated as a request for the execution of its function. On the receiving the message the appropriate function of the object is invoked and thus desired results are produced. 4.6 Inheritance and code reusability Inheritance is where one class (child class) inherits the members of another class (parent class).the benefit of inheritance is that the child class doesn't have to redeclare and redefine all the members which it inherits from the parent class. It is therefore a way to re-use code. Inheritance also enables you to write generic code which applies to all classes in an inheritance hierarchy. You can do this because you know that all child classes must contain the same members as the parent class. Here's a very simple example which illustrates these points. Note in particular that: ParentMethod is inherited by the Child class and so doesn't have to be redeclared or redefined. Although TestMethod takes a parameter of type Parent we can nevertheless pass it a Child object as well. This is because Child must contain the same members as Parent and so is implicitly convertible to it. class Parent public void ParentMethod() Cout<<"Hello from parent method"; class Child : Parent public void ChildMethod() Cout<<"Hello from child method"; void main() Child c = new Child(); c.parentmethod(); c.childmethod(); TestMethod(c); ISSN Page 46 References [1] Robert David Cowan, Ali Mili, Hany Ammar, Alan McKendall Jr. Software Engineering Technology Watch. IEEE Software, Volume 19, Number 4, Jul./Aug. 2002, pp [2] E. Levenez. Computer Language History. [3] Kenneth C. Louden. Programming Language Principles and Practice. PWS Publishing Company, Boston, MA [4] U.S. Department of Defense. June Department of Defense Requirements for High Order Computer Programming Languages: Steelman. [5] S Findy and B. Jacobs, How To Design A Programming Language,

5 2002. [6] Principal Components and Factor Analysis, [7] Edwards, A.L. Multiple Regression And The Analysis Of Variance And Covariance 2 nd ed W.H.freeman and Company. [8] Geoffrey A. Moore. Crossing the Chasm. Harper Business, ISSN Page 47

Oops known as object-oriented programming language system is the main feature of C# which further support the major features of oops including:

Oops known as object-oriented programming language system is the main feature of C# which further support the major features of oops including: Abstraction Encapsulation Inheritance and Polymorphism Object-Oriented