Object oriented programming concepts in php

In this session we will study some object oriented programming concepts in the php like classes and constructor.

To study the oop’s concept in php follow the steps given below :

Install Xampp server in your machine and if it is already installed go to xampp->htdocs folder .

Create a new folder say s7 in the htdocs folder.

Inside this s7 folder create a new folder called as classes .

Inside the classes folder create a file say car.php .

Now open the car.php file with notepad++ or any other text editor .

Now write the given code in car.php file :

<?php class Car          private $model;   private $color;   private $make;      public function start()        echo 'Car is starting....';        public function setMake($make)        $this->make=$make;           public function getMake()        return $this->make;    ?>

Note: Here we will first set the value using the setMake() function and access it using the getMake() function .

Now in the classes folder create another file say index.php .

Open it with notepad++.

Write the given code in the index.php file

<?php include 'classes/car.php'; $car1=new Car();  // Create an object of an car class $car1->setMake('Honda City');   //Get the element of an car class. echo $car1->getMake(); ?>

You will have the following view of your notepad++ window :

Now from the xampp control pannel start the apache and mysql modules and then open up the browser and enter the following url http://localhost/s7/

You will have the following output :

We can also use constructors in php , the syntax is :

public function __construct()    code..;  

Now let’s implement constructor in the following example :

Create an new folder in the htdocs folder say s8

In this s8 folder create another folder called as classes and a new file say index.php

In the classes folder create a new file called as car.php

Now write the given code in the car.php file :

<?php class Car          private $model;   private $color;   private $make;      public function __construct()        echo 'Car is starting....';       ?>

Thus your notepad++ window will have the following view :

Now write the given code in index.php file which is present in the s8 folder .

<?php include 'classes/car.php'; $car1=new Car();  // Create an object of an car class ?>

You will have the following view of your notepad++ window :

Now to get the output just enter the following url http://localhost/s8/

We can also pass parameters to the constructors .

Now edit the car.php file and replace the code with the given one :

<?php class Car          private $model;   private $color;   private $make;      public function __construct($model,$make,$color)          $this->make=$make;    $this->model=$model;    $this->color=$color;         public function getColor()         return $this->color;       ?>

You will have the following view of your notepad++ window :

Also edit the index.php file and add the following code in it :

<?php include 'classes/car.php'; $car1=new Car('Tata','Accord','Red');  // Create an object of an car class echo $car1->getColor();               //Call the method getColor() in our car.php file ?>

You will have the following view of your notepad++ window :

Enter the following url in the browser http://localhost/s8/

Hence you will have the following output :

Note: If we create an another object say car2 by calling the same function then the previous objects value gets appended to the newly created objects value.

So if you edit the code as shown below :

And run your project the you will have the following output as shown in the image .