PHP ??? ??? ????? ??? ???? ??? ?? ??? ???? ?????. ???? ?? ???? ?? ??(?: ??? ??? ??), ??? ??(?: ????? ??) ? ?? ??(?: ??? ??)? ?????. ??? ??? ???? ??? ????, ?? ???? ????, ???? ??? ? ?? ?????. ????? ????? ??? ??? ????? ?? ?? ?? ?? ????? ??? ? ????. ????? PHP ??? ??? ???? ?? ???? ?? ?? ??? ??????? ??? ? ??? ?????.

PHP ??? ??: ?? ????? ??? ?? ???

??? ??? ????? ??? ???? ??? ?? ??? ??????. PHP? ??? ??? ??? ?? ??? ?? ???? ???? ?? ??? ??? ??????? ????? ?? ? ????.

??? ?? ????

??? ??? ????? ??? ??, ??? ??, ?? ???? ?????. ??? ? ?? ???? ????.

• ??? ??: Singleton, Factory Method, Builder
• ??? ??: Decorator, Facade, Proxy
• ?? ??: Strategy, Command, Observer

?? ??? ??? ??

??? ??? ??? ?? ??? ?? ?????? ???? ?? ?? ????, ?? ??? ???? ??? ?????? ?? ?????. ?? ?? ?? ?? ????? ?? ????? ??? ??? ???????.

?? ?:

interface VehicleInterface
{
    public function createVehicle();
}

class CarFactory implements VehicleInterface
{
    public function createVehicle()
    {
        return new Car();
    }
}

class BikeFactory implements VehicleInterface
{
    public function createVehicle()
    {
        return new Bike();
    }
}

// 使用工廠
$carFactory = new CarFactory();
$car = $carFactory->createVehicle();

$bikeFactory = new BikeFactory();
$bike = $bikeFactory->createVehicle();

??? ??? ?? ??????

??? ??? ?? ????? ??? ?? ????. ??? ?? ??? ???? ?? ????? ??? ????.

• ???? ??? ???? ?? ????? ?????.
• ??? ??? ???? ???? ??? ?? ???? ?????.
• ??? ???? ?? ???? ??????.

?? ??: ?? ??? ???? ??? ??

?? ??? ????? ????? ???? ??? ????? ??? ? ?? ??? ?? ??????? ???. ??? ??? ??? ???? ?????.

PHP?? SplSubject 和 SplObserver ???? ??? ??? ?? ??? ?????.

class Cart implements SplSubject
{
    private $observers = [];
    private $items = [];

    public function attach(SplObserver $observer)
    {
        $this->observers[] = $observer;
    }

    public function detach(SplObserver $observer)
    {
        if (in_array($observer, $this->observers)) {
            unset($this->observers[array_search($observer, $this->observers)]);
        }
    }

    public function notify()
    {
        foreach ($this->observers as $observer) {
            $observer->update($this);
        }
    }

    public function addItem($item)
    {
        $this->items[] = $item;
        $this->notify();
    }

    public function removeItem($item)
    {
        $key = array_search($item, $this->items);
        if ($key !== false) {
            unset($this->items[$key]);
            $this->notify();
        }
    }
}

class OrderStatusObserver implements SplObserver
{
    public function update(SplSubject $subject)
    {
        if ($subject instanceof Cart) {
            echo "Order status has been updated.\n";
        }
    }
}

// 使用觀察者模式
$cart = new Cart();
$orderStatusObserver = new OrderStatusObserver();
$cart->attach($orderStatusObserver);

// 模擬添加和刪除商品
$cart->addItem('Item A');
$cart->removeItem('Item B');

??

PHP ??? ??? ???? ???? ????? ?? ??? ???? ? ??? ? ? ?? ??? ?????. ??? ??? ???? ???? ???? ?? ???? ?? ?? ??? ??????? ?? ? ????.

? ??? PHP ??? ??: ?? ????? ??? ???? ? ???? ??? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!