PHP常见设计模式

• 简单工厂

<?php
 # 简单工厂
 abstract class mycoach
 {
     public function __construct(){}
 }
 
 class cultivatecpc extends mycoach{
     public function __construct(){
         echo "把陈培昌培养为搏击教练"."
";
     }
 }
 
 class cultivatecj extends mycoach{
     public function __construct(){
         echo "把程劲培养为搏击教练"."
";
     }
 }
 
 class martialclub 
 {
     public function cultivate($name)
     {
         switch($name){
             case 'cj':
                 return new cultivatecj();
             case 'cpc':
                 return new cultivatecpc();
             default:
                 echo '培养一个小教练'."
";
                 break;
         }
         return null;
     }
 }
 class clubmaster{
     public function cultivate()
     {
         $myclub = new martialclub();
         $myclub->cultivate('cj');
         $myclub = new martialclub();
         $myclub->cultivate('cpc');
     }
 }
 
 $mymaster = new clubmaster();
 $mymaster->cultivate();

输出结果：

把程劲培养为搏击教练
把陈培昌培养为搏击教练

•  （复杂）工厂

<?php
abstract class mycoach
{
    public function __construct()
    {}
}

class cpc extends mycoach
{
    public function __construct()
    {
        echo "培养出了搏击教练昌仔"."
";
    }
}

class cj extends mycoach
{
    public function __construct()
    {
        echo "培养出了搏击教练劲儿弟弟"."
";  
    }
}

interface cultivate{
    function cultivate();
}

class cultivatecpc implements cultivate
{
    public function cultivate()
    {
        return new cpc();
    }
}

class cultivatecj implements cultivate
{
    public function cultivate()
    {
        return new cj();
    }
}

class coach{
    public function __construct()
    {
        $coach = new cultivatecpc();
        $coach->cultivate();
        
        $coach = new cultivatecj();
        $coach->cultivate();
    }
}

$littlecoach = new coach();

输出结果：

培养出了搏击教练昌仔
培养出了搏击教练劲儿弟弟

•  观察者模式

<?php
 class watcher
 {
     private $name;
     public function __construct($myname){
         $this->name=$myname;
     }
     public function update($food)
     {
         switch($food)
         {
             case '奶油蛋糕':
                 echo $food."上桌了，".$this->name.'取出了一份纸盘子和塑料叉子,切了一块'."
";
                 break;
             case '烤鸭':
                 echo $food."上桌了，".$this->name.'取了张薄饼，夹了些许葱丝，刷了些甜面酱'."
";
                 break;
             default:
                 echo $food."上桌了，".$this->name."赶紧加了两筷子"."
";
                 break;
         }
         return null;
     }
 }
 
 class watchee
 {
     private $watchlist = [];
     public function addwatcher($watcher)
     {
         $this->watchlist[]=$watcher;
     }
     public function removewatcher($watcher)
     {
         $target = array_search($watcher,$this->watchlist);
         $target = (int)$target;
         unset($this->watchlist[$target]);
         //echo $target."
";
     }
     public function loaddish($dishname)
     {
         $this->notify($dishname);
     }
     public  function  notify($dishname)
     {

　　　　　　#这里推荐用foreach循环，for循环带来的陷阱是，如果以数字为索引，执行removewatcher方法后，有些索引就没了，访问不到就会报错

　　　　foreach($this->watchlist as $k=>$v)
       {
             $this->watchlist[$k]->update($dishname);
       }
     }
     
 }
 
 $cpc = new watcher('陈培昌');
 $cj = new watcher('程劲');
 $observee = new watchee();
 $observee->addwatcher($cpc);
 $observee->addwatcher($cj);
 $observee->loaddish('葱香四川凉面');
 $observee->removewatcher($cj);
 $observee->loaddish('奶油蛋糕');
 $xxd = new watcher('徐晓冬');
 $observee->addwatcher($xxd);
 $observee->loaddish('避风塘茄子');

输出结果：

葱香四川凉面上桌了，陈培昌赶紧加了两筷子
葱香四川凉面上桌了，程劲赶紧加了两筷子
奶油蛋糕上桌了，陈培昌取出了一份纸盘子和塑料叉子,切了一块
避风塘茄子上桌了，陈培昌赶紧加了两筷子
避风塘茄子上桌了，徐晓冬赶紧加了两筷子