Object Oriented Programming(OOP) in PHP

PHP supports Object-Oriented Programming (OOP), allowing developers to use classes and objects to structure their code. Here's an overview of key OOP concepts in PHP:

1. Classes and Objects:

Creating a Class:

A class is a blueprint for creating objects. It defines properties (attributes) and methods (functions) that the objects will have.

class Car {
    // Properties
    public $make;
    public $model;

    // Methods
    public function startEngine() {
        echo "Engine started!";
    }
}

Creating Objects:

Objects are instances of a class. You create objects using the new keyword.

// Create an object of the Car class
$myCar = new Car();

// Accessing properties and calling methods
$myCar->make = "Toyota";
$myCar->model = "Camry";
$myCar->startEngine();

2. Constructor and Destructor:

Constructor:

A constructor is a special method that is automatically called when an object is created. It is used to initialize object properties.

class Car {
    public $make;
    public $model;

    // Constructor
    public function __construct($make, $model) {
        $this->make = $make;
        $this->model = $model;
    }
}

Destructor:

A destructor is a special method that is automatically called when an object is no longer referenced. It can be used to perform cleanup tasks.

class Car {
    // ...

    // Destructor
    public function __destruct() {
        echo "Car object destroyed!";
    }
}

3. Inheritance:

Inheritance allows a class to inherit properties and methods from another class. The extends keyword is used for inheritance.

class Truck extends Car {
    public $payload;

    public function loadCargo() {
        echo "Cargo loaded!";
    }
}

4. Encapsulation:

Encapsulation involves bundling the data (properties) and methods that operate on the data within a single unit (class). Properties are often declared as private or protected, and public methods are used to access or modify them.

class BankAccount {
    private $balance;

    public function __construct($initialBalance) {
        $this->balance = $initialBalance;
    }

    public function deposit($amount) {
        $this->balance += $amount;
    }

    public function getBalance() {
        return $this->balance;
    }
}

5. Polymorphism:

Polymorphism allows objects of different types to be treated as objects of a common base type. It is achieved through method overriding and interfaces.

interface Shape {
    public function calculateArea();
}

class Circle implements Shape {
    public $radius;

    public function calculateArea() {
        return 3.14 * $this->radius * $this->radius;
    }
}

class Rectangle implements Shape {
    public $length;
    public $width;

    public function calculateArea() {
        return $this->length * $this->width;
    }
}

6. Abstraction:

Abstraction involves simplifying complex systems by modeling classes based on essential properties and behaviors. Abstract classes and interfaces are used to achieve abstraction.

abstract class Shape {
    abstract public function calculateArea();
}

class Circle extends Shape {
    // ...
}

class Rectangle extends Shape {
    // ...
}

These are some of the fundamental concepts of Object-Oriented Programming in PHP. They provide a structured and modular approach to software development, making it easier to design, maintain, and scale applications.

Thank you.