策略模式

// 策略的接口定义策略的所有行为
interface Animal {
    public function run();
    public function eat();
} 

// 实现接口的所有方法
class Cat implements Animal {
    public function run()
    {
        echo "cat run";
    }
    public function eat()
    {
        echo "cat eat";
    }
} 

// 实现接口的所有方法
class Dog implements Animal  {
    public function run()
    {
        echo "dog run";
    }
    public function eat()
    {
        echo "dog eat";
    }
} 


class MyAnimal
{

    protected $animal;
    public function __construct(Animal $animal)
    {
        $this->animal = $animal;
    }

    public function get()
    {
       $this->animal->run();
       $this->animal->eat();
    }
}

$MyAnimal = new MyAnimal(new Cat());
$MyAnimal->get();

$MyAnimal = new MyAnimal(new Dog());
$MyAnimal->get();

　　

策略模式实现了硬编码到解耦。