PHP类的设计模式

• 单例模式

<?php
class mysingle
{
    private static $myinstance =null;
    private function __construct()
    {
    }
    private function  __clone()
    {

    }
    public static function createobject()
    {
        if (self::$myinstance==null)
        {
            self::$myinstance = new self();
        }
        return self::$myinstance;
    }
}
$thesingle = mysingle::createobject();
$anothersingle = mysingle::createobject();
echo ($thesingle===$anothersingle);
?>

输出结果:

1

说明两个对象完全一致

• 观察者模式

被观察者（dingdaguo）做出某种行为(drink_cola())时，触发监控者(coach)的做出一些反应(persuade)

<?php
class dingdaguo
{
     protected $observers = [];
     public function addobserver($myobserver)
     {
        $this->observers[] = $myobserver;
     }
     public function drink_cola()
     {
        foreach($this->observers as $observer)
        {
            $observer->persuade();
        }
     }
     public function delobsrver($observer)
     {
         $index = array_search($observer,$this->observers,);
         $this->observers=array_slice($this->observers,0,$index);
     }
}

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

    public function persuade()
    {
        echo $this->name."说:别喝可乐了，都是甜的东西".PHP_EOL;
    }
}
$cpc = new coach("陈培昌");
$cj = new coach("程劲");
$dy = new dingdaguo();
$dy->addobserver($cpc);
$dy->addobserver($cj);
$dy->drink_cola();
echo "删除其中一个对象".PHP_EOL;
$dy->delobsrver($cj); 
$dy->drink_cola();

输出结果:

陈培昌说:别喝可乐了，都是甜的东西
程劲说:别喝可乐了，都是甜的东西
删除其中一个对象
陈培昌说:别喝可乐了，都是甜的东西

• 适配器

实现接口的过程中，所有类都按照一种方式实现接口

<?php
interface martial_trainning
{
    public function welcomeword();
    public function braziljudo();
    public function muaythai();
}
class xxd
{
    public function welcomeword()
    {
        echo "欢迎来到必图训练".PHP_EOL;
    }
}
class cj
{
    public function braziljudo()
    {
        echo "我是小烤肠，来跟我一起学巴西柔术吧".PHP_EOL;
    }
}

class cpc implements martial_trainning
{
    protected $myxxd = null;
    protected $mycj = null;
    public function __construct($xxd,$cj)
    {
        $this->myxxd = $xxd;
        $this->mycj = $cj;
    }
    public function welcomeword()
    {
        // TODO: Implement welcomeword() method.
        $this->myxxd->welcomeword();
    }
    public function braziljudo()
    {
        // TODO: Implement braziljudo() method.
        $this->mycj->braziljudo();
    }
    public function muaythai()
    {
        echo "我是小松鼠，跟我一起练习泰拳吧".PHP_EOL;
    }
}

$cj = new cj();
$xxd = new xxd();
$cpc = new cpc($xxd,$cj);
$cpc->braziljudo();
$cpc->welcomeword();
$cpc->muaythai();
?>

输出结果:

我是小烤肠，来跟我一起学巴西柔术吧
欢迎来到必图训练
我是小松鼠，跟我一起练习泰拳吧

• 策略模式

通过可以预测的参数传入，来决定调用哪个类的实现

<?php
interface martial_trainning
{
    public function hoaring();
}
class xxd implements martial_trainning
{
    public function hoaring()
    {
        echo "诶斯~诶斯~".PHP_EOL;
    }
}
class cj implements martial_trainning
{
    public function hoaring()
    {
        echo "诶~嘿嘿".PHP_EOL;
    }
}
class cpc implements martial_trainning
{
    public function hoaring()
    {
       echo "嗷儿喂~嗷儿喂~";
    }
}
class mycoach
{
    protected $myobject = null;
    public function  __construct($whichobject)
    {
        $this->myobject = $whichobject;
    }
    public function hoaring()
    {
        $this->myobject->hoaring();
    }
}
$cpc = new cpc();
$mycoach = new mycoach($cpc);
$mycoach->hoaring();
echo PHP_EOL."===========换了一个类=============".PHP_EOL;
$cj = new cj();
$mycoach = new mycoach($cj);
$mycoach->hoaring();
?>

输出结果：

嗷儿喂~嗷儿喂~
===========换了一个类=============
诶~嘿嘿