Programming Language Definition

Programming Language Definition: A sequence of instructions that a computer can interpret and execute to complete task is called computer program. The language which is used to develop a computer program is called programming language. There are two types of programming language which are procedure oriented programming language and object oriented programming language.
1.       Procedure Oriented programming:Conventional programming, using high level languages such as COBOL, FORTAN and C is commonly known as procedure oriented programming (POP). In the procedure oriented approach, the problem is viewed as a sequence of things to be done such as reading, calculating and printing. Procedure oriented programming basically consists of writing a list of instructions (or actions) for the computer to flow and organizing these instructions into groups known as functions.

Characteristics of Procedure Oriented Programming
i)        Emphasis is on doing things (algorithms)
ii)       Large Programs are divided into smaller Programs Known as functions.
iii)     Most of the functions share global data
iv)     Data move openly around the system from function to function.
v)      Functions transform data from one to another.
vi)     Employs top-down approach in program design.

Drawbacks of Procedure Oriented Programming
i)        In large program it is very difficult to identify what data is used by which function. In case we need to revise an external data structure, we also need to revise all functions that access the data. This provides an Opportunity for bugs to creep in.
ii)       With the procedural approach is that it does not model real world problems very well. This is because functions are action oriented and do not really corresponding to the elements of the problem.

2.       Object-oriented Programming: Object oriented programming treats data as a critical element in the program development and does not allow it to flow freely around the system. It ties data more closely to the functions that operate on it, and protects it from accidental modification from outside functions. OOP allows decomposition of a problem into a number of entities called objects and then builds data and functions around these objects.

Characteristics of Object-Oriented programming
i)        Emphasis is on data rather than procedure.
ii)       Programs are divided into what are known as objects.
iii)     Data structures are designed such that they characterize the objects.
iv)     Functions that operate on the data of an object are tied together on the data structure.
v)      Data is hidden and cannot be accessed by external functions.
vi)     Objects may communicate with each other through functions.
vii)   New data and functions can be easily added whenever necessary. Follows bottom up approach is program design.

Benefits of Object Oriented Programming
i)        Through inheritance we can eliminate redundant code and extend the use of existing classes.
ii)       We can build programs from the standard working modules that communicate with one another, rather than having to start writing the code from scratch. This leads to saving of development time and higher productivity.
iii)     The principle of data hiding helps the programmer to build secure programs that cannot be invaded by code in other parts of the program.

Some terms used in Object Oriented Programming

Ø  Objects: Objects are basic run-time entities in an object oriented system.
Ø  Classes: A class is a collection of objects of similar type.
Ø  Data Abstraction and Encapsulation: The wrapping up of data and functions into a single unit is known as encapsulation.
Abstraction refers to the act of representing essential features to the act of representing essential features without including the background or explanations.
Ø  Inheritance: Inheritance is the process by which objects of one class acquire the properties of objects of another class.
Ø  Polymorphism: Polymorphism is another important OOP concept. Polymorphism, a Greek term means the ability to take more than one form. The operation may exhibit different instances the behavior depends upon the types of data is the operation.
Ø  Dynamic Binding: Binding refers to the linking of a procedure call to the code to be executed in response to the call. Dynamic binding (also known as late binding) means that the code associated with a given procedure call is not known until the time of the call at run time.
Ø  Message passing: A message for an object is a request for execution of a procedure and therefore will invoke a function (procedure) in the receiving object that generates the desired result.