PHPデザインパターンの戦略パターンを詳しく解説

<?php
/*
 *策略模式
 */
interface FlyBehavior
{
    public function fly();
}

class FlyWithWings implements FlyBehavior
{
    public function fly()
    {
        echo "鸭子用翅膀飞行 \n";
    }
}

class FlyWithNo implements FlyBehavior
{
    public function fly()
    {
        echo "鸭子不用翅膀飞行 \n";
    }
}

class Duck
{
    private $_flyBehavior;

    public function performFly()
    {
        $this->_flyBehavior->fly();
    }

    public function setFlyBehavior(FlyBehavior $behavior) //被外部调用设置策略的
    {
        $this->_flyBehavior = $behavior;
    }
}

class RubberDuck extends Duck
{
}

// Test Case
$duck = new RubberDuck();

/*  想让鸭子用翅膀飞行 */
$duck->setFlyBehavior(new FlyWithWings());
$duck->performFly();

/*  想让鸭子不用翅膀飞行 */
$duck->setFlyBehavior(new FlyWithNo());
$duck->performFly();