关于php继承的问题

class base{
    public $dog = array('color'=>'red','age'=>3);
}
class one extends base{
    public function set($key,$value)
    {
        $this->dog[$key] = $value;
    }
}

class two extends base{
    public function set($key,$value)
    {
        $this->dog[$key] = $value;
    }
}
$one = new one();
$two = new two();
$one->set('color','yellow');
print_r($one->dog);//Array ( [color] => yellow [age] => 3 )
print_r($two->dog);//Array ( [color] => red [age] => 3 )

想要$one对象改变了dog属性之后，$two对象的dog属性也跟着改变，就要引用的那样，不知道要怎样实现？

回复内容：

class base{
    public $dog = array('color'=>'red','age'=>3);
}
class one extends base{
    public function set($key,$value)
    {
        $this->dog[$key] = $value;
    }
}

class two extends base{
    public function set($key,$value)
    {
        $this->dog[$key] = $value;
    }
}
$one = new one();
$two = new two();
$one->set('color','yellow');
print_r($one->dog);//Array ( [color] => yellow [age] => 3 )
print_r($two->dog);//Array ( [color] => red [age] => 3 )

想要$one对象改变了dog属性之后，$two对象的dog属性也跟着改变，就要引用的那样，不知道要怎样实现？

static 静态关键字

    class base{
        public static $dog = array('color'=>'red','age'=>3);
    }
    class one extends base{
        public function set($key,$value)
        {   
            parent::$dog[$key] = $value;
        }   
    }

    class two extends base{
        public function set($key,$value)
        {   
            parent::$dog[$key] = $value;
        }   
    }
    $one = new one();
    $two = new two();
    $one->set('color','yellow');
    print_r($one::$dog);//Array ( [color] => yellow [age] => 3 )
    print_r($two::$dog);//Array ( [color] => red [age] => 3 )

单例 静态属性

补充@ 徐先生的背影

LZ应该注意代码中的parent，parent指向父类
如果换成self那么就是指向当前类

@徐先生的背影 的回答解决了你的问题，但是我觉得你可能对类和对象的理解有问题。 @pang20c 的答案就是我指的。
你把你那句 $two=new two() 改为 $two=new one() 结果还是一样的。

    print_r($one->dog);//Array ( [color] => yellow [age] => 3 )
    print_r($two->dog);//Array ( [color] => red [age] => 3 )

也可能是我想多了。。。。不过问题基本解决了

class two extends one{
}