<?php
abstract class Strategy
{
    abstract function goSchool();
}
class Run extends Strategy
{
    public function goSchool() {
        echo "走路去學(xué)校";
    }
}
class Subway extends Strategy
{
    public function goSchool() {
        echo "地鐵去學(xué)校";
    }
}
class Bike extends Strategy
{
    public function goSchool() {
        echo "公交去學(xué)校";
    }
}
class GoSchoolContext
{
    protected $_stratege;
    public function __construct($stratege) {
        $this->_stratege = $stratege;
    }
    public function goSchool()
    {
        $this->_stratege->goSchool();
    }
}
$traget = new Run();
$obj = new GoSchoolContext($traget);
$obj->goSchool();

適配器模式

特點

需要的東西在面前，但卻不能用，而短時間又無法改造它，于是就想辦法適配

實現(xiàn)

// 適配器
interface Charget
{
    public function putCharget();
}
class China implements Charget
{
    private $v = 220;
    public function putCharget()
    {
        return $this->v;
    }
}
class Adper extends China
{
    public function putCharget() {
        return parent::putCharget() / 2 + 10;
    }
}
class Phone
{
    public function charge(Charget $charge)
    {
        if ($charge->putCharget() != "120") {
            echo "不能充電";
        } else {
            echo "能充電";
        }
    }
}
$china = new China();
$adper = new Adper();
$phone = new Phone();
$phone->charge($adper);

觀察者模式

特點

當(dāng)一個對象狀態(tài)發(fā)生變化時, 依賴他的對象全部收到通知, 并主動更新。觀察者模式實現(xiàn)了低耦合, 非侵入式的通知與更新機制。

實現(xiàn)

<?php
// 主題接口
interface Subject
{
    public function register(Observer $observer);
}
// 觀察者接口
interface Observer
{
    public function watch();
}
// 主題
class WatchAction implements Subject
{
    public $_observers = [];
    public function register(\Observer $observer) {
        $this->_observers[] = $observer;
    }
    public function notify()
    {
        foreach($this->_observers as $object) {
            $object->watch();
        }
    }
}
// 觀察者
class Cat1 implements Observer{
    public function watch(){
        echo "Cat1 watches TV<hr/>";
    }
}
class Dog1 implements Observer{
    public function watch(){
        echo "Dog1 watches TV<hr/>";
    }
}
 class People implements Observer{
    public function watch(){
        echo "People watches TV<hr/>";
    }
 }
$action = new WatchAction();
$action->register(new Cat1());
$action->register(new People());
$action->register(new Dog1());
$action->notify();