Object Oriented Principles – OO Part 3

In this part, we’ll try to understand principles of object oriented, that of course we’ll implement it both in design analysis and programming as well.

Object
-> represent abstraction of real world things
-> object has status, identity and behaviour

Class, attribute and operation/methode
Class
-> abstraction of an object
Attribute
-> defined data as part of class
Operation/methode
-> defined procedure or function as part of class.

Encapsulation and information hiding
Encapsulation
-> Object oriented concept that defines object as something contains data and methode that’s used to manipulate the data
Information Hiding
-> hiding internal data’s detail implementation and method/operation of other’s object. Information hiding prevents a change of program because of a little mistake in object’s implementation

Message passing, inheritance and polimorfism
Message Passing
-> communication among objects to send a command or information
Inheritance
-> sharing of attributes and methodes among classes that’s related hierarchily that’s represented as superclass and subclass in its implementation.
Polimorfism
-> a mechanism to hide different implementation behind a same interface

Relation
Kind of relation :
-> link : relation between objects for a certain services
-> Association : a bunch of same structure and semantic links
-> Generalization/Specialization : inheritance’s implementation

Agregation :
Some definitions of agregation:
-Assembly parts composition
-> A whole object built of part objects that still have their real identity though they’ve become part of a whole object. Ex: a monitor is a part of a computer

-Material object composition
-> A whole object built of lost real indentity part objects. Ex: a candy made of sugar

-Portion object composition (homeomorfism)
-> A whole object is itself part objects. Ex: a spoonful of cereal is a portion of a bowl of cereal

-Place area composition (homeomorfism)
-> Ex: New York city is a part of New York State

-Collection member composition (homeomorfism)
-> Ex: A monthly work’s shift contains of a daily work’s shift

-Container content composition
-> define a collection of parts object as a whole object. Container can be defined though there’s no content. Ex: A company – workers

-Member partnership composition
-> define a collection of parts object as a whole object. Container can’t be defined though there’s no content.Ex: Booch, Jacobson, Rumbaugh as authors of the UML book