PHP オブジェクト指向プログラミングの 4 つの主要な機能の分析

class Person {
    private $name;
    private $age;

    public function __construct($name, $age) {
        $this->name = $name;
        $this->age = $age;
    }

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

    public function getAge() {
        return $this->age;
    }
}

$person = new Person("John", 25);
echo $person->getName();  // 输出：John
echo $person->getAge();   // 输出：25

class Animal {
    protected $name;

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

    public function eat() {
        echo $this->name . " is eating.";
    }
}

class Dog extends Animal {
    public function bark() {
        echo $this->name . " is barking.";
    }
}

$dog = new Dog("Tom");
$dog->eat();   // 输出：Tom is eating.
$dog->bark();  // 输出：Tom is barking.

class Animal {
    public function makeSound() {
        echo "Animal is making sound.";
    }
}

class Cat extends Animal {
    public function makeSound() {
        echo "Cat is meowing.";
    }
}

class Dog extends Animal {
    public function makeSound() {
        echo "Dog is barking.";
    }
}

$animals = array(new Cat(), new Dog());
foreach ($animals as $animal) {
    $animal->makeSound();
}

abstract class Shape {
    abstract public function getArea();
    abstract public function getPerimeter();
}

class Rectangle extends Shape {
    private $length;
    private $width;

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

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

    public function getPerimeter() {
        return 2 * ($this->length + $this->width);
    }
}

$rectangle = new Rectangle(5, 3);
echo "Area: " . $rectangle->getArea();         // 输出：Area: 15
echo "Perimeter: " . $rectangle->getPerimeter(); // 输出：Perimeter: 16