Hey Guys !!!! Normally I am busy. But today I got some free time so I
think I should write something about the OOP programming approach and
Procedure Programming approach. Because many new programmer like me
always get confuse between OOP because we create primarily procedural
code.

Lets understand these one by one and understand the differences. :)

In procedure programming approach or procedure oriented approach, the
problems is viewing  in a sequence of things or tasks. And these tasks
are accomplished by the functions or we can say that we write the
functions to accomplish these tasks. This approach basically consists of
writing a list of instructions and organizing these instructions into
group known as function. In this approach because we concentrate on the
development of the functions thats why very little attention is given to
the data.

While in the OOP data is treated as a critical elements in the program
and does not allow it to flow freely in the system. OOP allows
decomposition of a problem into a number of entities called objects and
then build data and functions around these objects. So this the basic
definition of OOP and Procedure programming or we can say that basic
difference between them. Now lets get some more about these:-

Functions are Code-Centric which means that data first sent as input and
then return as output. While OOP is Data-Centric which means that data
is internally represent and contains the functionality or method. In OOP
objects contain data and behavior simultaneously while Function contain
data and function separated.

OOP require a different way of thinking about how you construct your
applications.OOP is basically all about Classes and Objects. Lets
understand the concept of OOP one by one.

To understand OOP let us take an example of a car. A car have its own
color,weight, manufacturer, gas tank etc. Those are its characteristics.
While a car can accelerate,stop,sound for horn etc. Those are its
behavior. And a car is itself a class which have characteristics and
behavior. A class is basically nothing  but a unit of code. Now lets
come again on our example of a car.

The characteristics of car are known as its properties. Properties have a
name and value and they may be vary or not. Like we can change the
color of a car by giving its new paint job. So, what are properties in
OOP these are nothing but the variable declared within a class. Which
have its own name and value. These properties can be variable or
constant or static. And the behavior of a class is also known as method.
And we can say that a method is nothing but it its similar to a
function which we normally used in procedural programming.

Some concept of OOP are given below:-

Classes:-As we say that classes are nothing but the
code which defines the properties and method. Class in PHP contains
three main components: a members,method and a constructor. A member is a
piece of data that an object can contains. In our car example color and
manufacturer are members of class car. Methods are the services which
are provided to client by the object or we can say that method are
functions. A method is also known as member function. And a constructor
is special method that initialize the objects into its ready state.

Example of how to define a class in PHP is given below:-

<?php

class demo {     // class is keyword used in php to declare a class and demo is class name here.

}

?>   

Objects:- Objects are the entities constructed by a class.
It is an instance of the class. The process of building an object from a
class is known as instantiation.A class can have more than one object.
An example for object is given below:-

<?php



$objdemo=new demo();  // here we define a object for class demo using keyword new. New keyword is used to define a object for a class.



?>

Inheritance:- Inheritance is process by which objects of one
class acquire the properties of the objects of another class or we can
say that parent class. Inheritance provides the idea of reusability. We
can reuse a code either by copy it and paste it in another or by using
Inheritance. The copy paste method have major problem is that if we
found an error in our main code then we have to debug all the pasted
code. Thats why its good to use Inheritance and by using it we can
modify a code without changing its main properties. Extends keyword is using for Inheritance. Example of Inheritance is given below:-

<?php

class media {

---declare some members----

function somefun(){

--some code---

}

}

class books extends media {

----some new members for books class which is subclass of media class---

function somenewfun()

{

--code for new methods for books class--

}

}

?>

Here in this example I used two class one is media which is our parent
class and another is book which is our subclass. The subclass book have
all the properties and methods from the parent class media and it is
also have its own properties and methods which we declare in the book
class. The  extands keyword is used to Inherit all the properties and methods of parent class to its subclass.

NOTE:- Don't forget to change the lines --declare
members-- or --code for method-- to your original logic before running
the program in PHP.



I think this is sufficient for this section. Others properties like
polymorphism and access methods for a class is given to the next
section. Thanks for tolerating me this long time..:p;).. Hope this will
be helpful for some of you guys..:).. Thank You all..