01-02-2012, 03:47 PM
MODERN APPLICATIONS OF OBJECT-ORIENTED LANGUAGES
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INTRODUCTION
With introduction of graphical operating systems such as Windows, a new concept of programming has emerged. Programmers now design applications by putting together different pieces of already-written code that has been tested before, and each piece of code is called an “Object” [1]. Objects can have properties such as color, shape, size and data type. Because of underlying operating system behind it, its properties can be set rather than writing a lot of code. Not only that, one can create an application with an underlying database behind it, using all pre-programmed templates based upon the structure of the database.
Object-Oriented Concepts
Object-Oriented Concepts can be broken down into four properties:
• Inheritance
• Encapsulation
• Polymorphism
• Abstraction
Inheritance:
Developers reuse existing objects through the inheritance mechanism that most Object-Oriented tools provide. Inheritance is a critical concept of Object-Orientation, because it lets developers inherit the capabilities (methods and data) of existing objects. This lets developers maximize the use of application objects.
Developers can implement inheritance in two modes: single and multiple. Single inheritance allows the inheritance of information from a single object/class, whereas multiple inheritance allows objects to inherit information from two objects/class simultaneously.
Encapsulation:
This is one of the features of the Object-Oriented approach that has the most meaning for relational databases. Unlike a traditional relational implementation where data is manipulated by external applications and associates them with their base objects. Encapsulation makes data and methods without disturbing other portions of the application, as long as the external interfaces remain unchanged.
Polymorphism:
This is the ability of different objects to receive the same message and behave in different ways. It implies that a standard interface may be created for a related group of objects. The object’s specific action will depend on the message passed to the interface. Because the programmer is no longer concerned with the object’s internal constructs, one can create some extremely complex programs. Programmers only need to understand the interface to use the object.
