PHP object-oriented programming basics

PHP is a powerful programming language that supports object-oriented programming (OOP) concepts. Here are some basics of PHP OOP:

1. Classes and objects: A class is a blueprint for an object that defines its properties and methods. An object is an instance of a class.
2. Encapsulation: Encapsulation is the process of hiding the implementation details of a class from other parts of the code. In PHP, you can achieve encapsulation by using access modifiers like public, private, and protected.
3. Inheritance: Inheritance is the process of creating a new class based on an existing class. The new class inherits the properties and methods of the existing class and can add new properties and methods of its own.
4. Polymorphism: Polymorphism is the ability of an object to take on different forms or have different behaviors depending on the context. In PHP, polymorphism can be achieved through method overriding and method overloading.
5. Abstraction: Abstraction is the process of reducing complexity by hiding unnecessary details. In PHP, you can achieve abstraction by using abstract classes and interfaces.
6. Constructors and destructors: A constructor is a special method that is called when an object is created. A destructor is a special method that is called when an object is destroyed.

Here is an example of a basic PHP class:

class Car {
  private $make;
  private $model;
  private $year;

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

  public function getMake() {
    return $this->make;
  }

  public function getModel() {
    return $this->model;
  }

  public function getYear() {
    return $this->year;
  }
}

$car = new Car('Honda', 'Civic', 2021);
echo $car->getMake(); // Output: Honda
echo $car->getModel(); // Output: Civic
echo $car->getYear(); // Output: 2021

In this example, we define a Car class with three private properties (make, model, and year) and a constructor that sets these properties when a new Car object is created. We also define three public methods (getMake, getModel, and getYear) that can be used to retrieve the values of these properties. Finally, we create a new Car object and use its methods to retrieve its properties.