اصول OOP به صورت خلاصه همراه با کد

class User {
    private $name;

    public function setName($name) {
        $this->name = $name;
    }

    public function getName() {
        return $this->name;
    }
}

$user = new User();
$user->setName("John");
echo $user->getName(); // خروجی: John

abstract class Animal {
    abstract public function sound();
}

class Dog extends Animal {
    public function sound() {
        return "Bark";
    }
}

class Cat extends Animal {
    public function sound() {
        return "Meow";
    }
}

$dog = new Dog();
echo $dog->sound(); // خروجی: Bark

class Animal {
    public function eat() {
        return "Eating...";
    }
}

class Dog extends Animal {
    public function bark() {
        return "Barking...";
    }
}

$dog = new Dog();
echo $dog->eat(); // خروجی: Eating...
echo $dog->bark(); // خروجی: Barking...

interface Shape {
    public function area();
}

class Circle implements Shape {
    private $radius;

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

    public function area() {
        return pi() * pow($this->radius, 2);
    }
}

class Rectangle implements Shape {
    private $width, $height;

    public function __construct($width, $height) {
        $this->width = $width;
        $this->height = $height;
    }

    public function area() {
        return $this->width * $this->height;
    }
}

$circle = new Circle(5);
echo $circle->area(); // خروجی: مساحت دایره

$rectangle = new Rectangle(4, 5);
echo $rectangle->area(); // خروجی: مساحت مستطیل