Beverage.php
<?phpnamespace DesignPattern;abstract class Beverage{ ???/** ????* @var string ????*/ ???protected $name = ‘‘; ???/** ????* @return string ????*/ ???public function getName(): string ???{ ???????return $this->name; ???} ???/** ????* @param string $name ????* @return Beverage ????*/ ???public function setName(string $name): Beverage ???{ ???????$this->name = $name; ???????return $this; ???} ???/** ????* @return float ????*/ ???public abstract function getCost(): float; ???/** ????* Beverage constructor. ????*/ ???public function __construct() ???{ ???}}BlueMountainCoffee.php
<?phpnamespace DesignPattern;/** * 蓝山咖啡 */class BlueMountainCoffee extends Beverage{ ???/** ????* @return float ????*/ ???public function getCost(): float ???{ ???????return 18.0; ???}}CubitaCoffee.php
<?phpnamespace DesignPattern;/** * 琥爵咖啡 */class CubitaCoffee extends Beverage{ ???/** ????* @return float ????*/ ???public function getCost(): float ???{ ???????return 24.0; ???}}CoffeeDecorator.php
<?phpnamespace DesignPattern;abstract class CoffeeDecorator extends Beverage{ ???/** ????* @var CoffeeDecorator ????*/ ???protected $coffeeDecorator; ???/** ????* CoffeeDecorator constructor. ????* @param Beverage $coffeeDecorator ????*/ ???public function __construct(Beverage $coffeeDecorator)//特别需要注意这个地方，装饰者模式必须允许对装饰后的对象再次装饰 ???{ ???????parent::__construct(); ???????$this->coffeeDecorator = $coffeeDecorator; ???}}MilkDecorator.php
<?phpnamespace DesignPattern;class MilkDecorator extends CoffeeDecorator{ ???/** ????* @return float ????*/ ???public function getCost(): float ???{ ???????return $this->coffeeDecorator->getCost() + 2.5; ???}}SugarDecorator.php
<?phpnamespace DesignPattern;class SugarDecorator extends CoffeeDecorator{ ???/** ????* @return float ????*/ ???public function getCost(): float ???{ ???????return $this->coffeeDecorator->getCost() + 1.2; ???}}最终调用：
$coffee = new \DesignPattern\BlueMountainCoffee();//生成一杯蓝山咖啡$beverage = new \DesignPattern\MilkDecorator($coffee);//给蓝山咖啡加一份牛奶$beverage = new \DesignPattern\MilkDecorator($beverage);//给蓝山咖啡再加一份牛奶$beverage = new \DesignPattern\SugarDecorator($beverage);//给蓝山咖啡加一份糖$beverage = new \DesignPattern\SugarDecorator($beverage);//给蓝山咖啡再加一份糖$beverage = new \DesignPattern\SugarDecorator($beverage);//给蓝山咖啡再加一份糖var_dump($beverage->getCost());程序运行结果：
float(26.6)php设计模式之：装饰者模式
原文地址：https://www.cnblogs.com/foolishnoob/p/9261219.html