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Events and States

admin — Sun, 04 Mar 2012 04:09:46 +0000

Events States Anything that happen in time Shows the attributes values of object at a particular point in time An event separate two states A state separates two events An event is said to have happened without regard to whether it changes a state or not A state is said to have changed only if the event fired on the object changes [...]

Actors and Data Stores

admin — Sun, 04 Mar 2012 04:01:25 +0000

Actors:

Actors are objects represented in the functional model that produce or consume data. An actor may store some data for further processing steps.

Data Stores:

Data stores are store house of data represented in the functional model. A data store could only store or consume data, but could not produce data.

Below is an example detailing [...]

State Diagram – Car

admin — Sun, 04 Mar 2012 02:58:31 +0000

The state diagram may be drawn by considering the concurrency property of the aggregate objects that make up the car object ie. each aggregate object has a state of its own. Below is a sample state diagram for a Car object -

Below is the state diagram for Ignition System –

State Diagram – Transmission

State Diagram [...]

Object Diagrams with Multiple Inheritance

admin — Fri, 24 Feb 2012 03:34:25 +0000

Below is an example of implementation of multiple inheritance -

The Class ‘Universal’ inherits from two classes A/ and D/C, thus exhibiting multiple inheritance. Mutiple inheritance could be avoid by creating new class as below -

Universal Motors run both under A/C and D/C

Main features of Object Oriented Languages – Classes, Objects, Encapsulation, Polymorphism, Inheritance

admin — Fri, 24 Feb 2012 03:08:09 +0000

1. Classes and Objects

In an object oriented programming language, we code the program as a corporate collection of objects which are instantiated from various class abstractions. A class is only a logical abstraction and has no physical existence. An object is a specific instance of the class and it has physical existence inside the memory [...]

Abstraction

admin — Fri, 24 Feb 2012 02:40:50 +0000

Abstraction may be defined as all those essential characteristics features of an object class which makes it different from other object classes. Abstraction as applied to inheritance refers to the specific features defined for each subclass in the class hierarchy. Such a representation of the object class including only its essential attributes and operations, leaving [...]

Multiplicity

admin — Fri, 24 Feb 2012 02:18:56 +0000

Multiplicity refers to the number of object class instances of one class may be associated to the other class. An n+ symbol indicates that there can be n or >n associations of the object class near to the n+ symbol to the other associated class. A solid ball indicates 1 or >1 associations and a [...]

Inheritance

admin — Fri, 24 Feb 2012 02:13:17 +0000

Inheritance is the most basic feature of any Object Oriented programming language. It refers to the derivation of sub classes from a base/super class. The inherited sub classes inherit the common / basic features of the base / super class at the same time implements their own specific features. Inheritance helps us to reduce the [...]

Qualification

admin — Tue, 07 Feb 2012 04:15:32 +0000

Qualification is an association which involves an association and a qualifier which uniquely identifies certain features of one of the associated classes. Below example explains it. Multiplicity of association changed from many – many to many to 1.

Stock exchange + Ticker symbol = Company

Object Modeling Technique (OMT)

admin — Tue, 07 Feb 2012 03:52:01 +0000

Object Modeling Technique used in object oriented modeling and design which use the usual principles of system development like analysis, design an implementation but applying object oriented software design. Using OMT, we model design and implement the system in terms of real-world objects in the application domain. This involves the use of three different system [...]