PHP: Object Oriented Programming

Object oriented programming concepts were introduced in PHP1.4, I guess.
How many people around you play with object oriented programming?
If not working in any kind of MVC frameworks, I guess very short number of people.
Developers are often used to structured programming and don’t bother themselves learning object oriented programming concepts and paradigm.
Well, when software engineers realized that it’d become very difficult to manage and maintain thousand lines of code as well as impossible to represent real world object in computer world, object oriented programming was introduced. Since then dramatic improvements have been made to OOP.

In object oriented programming inheritance, polymorphism, encapsulation, dynamic binding and exception handling has great value, usage and advantages, however class and objects are the most basic concept.

Class is blue print containing properties and method associated with same entity. Object is the instance of the class and is used to access properties and method of the class.
In addition to OOP, design pattern make jobs easier for the programmers.
Singleton, factory and specially MVC design patterns are very useful these days.

In singleton design pattern one object of the class exist throughout the life cycle of the software application. If programmer tries to instantiate another object of the same class, a reference to the object instantiated earlier, is granted.

A class implementing factory design pattern works as bridge between multiple classes. Consider an example of using multiple database servers like SQL Server and Oracle. If you are developing an application using SQL Server database as backend, but in future need to change backend database to oracle, you will need to modify all your code, if you haven’t written your code following factory design pattern.
In factory design pattern you need to do very little work to achieve this. A class implementing factory design pattern takes care for you and lessen your burden. Switching from database server won’t bother you at all. You just need to make some small changes in your configuration file.

Revolution of MVC design patterns cause dramatic changes in software development life cycle. Prior to MVC, developers were mixing code all around. It was difficult to figure out where the business code resides and where presentation code is written. Intelligent software engineers, though, were trying hard to separate their business logic from presentation logic; this however wasn’t effective enough for new comers to understand their code and to do necessary maintenance. Without the help of the person behind the project, it’d taken more time to understand the directory structure used.
These draw backs were mostly addressed when MVC design patterns were introduced.

In MVC design pattern M stands for Model. Model contains your application’s business logic.
V stands for View. It’s the presentation layer.
While C stands for controller that work as glue between view and model. From glue I mean it takes data from view and give it to the model, model then process the data and produced desired results. The data, thus obtained, is given to the view. Controller can also be compared to event handlers. It responds to certain events such as posting the data back to server by clicking submitted data.
Hopefully I will unveil some other fact about OOP and design pattern later some time.