建造者模式

【风趣的解释】

Builder Mode

有时候带着MM去约会，KFC可能也是一个不错的约会地点，进去我们常常点上两个套餐，然后很happy的聊上一两个小时。有没有发现我们的选的套餐，都基本上是包括一个主食，几个辅食，一杯饮料呢？我们选好套餐，交了钱，收银员就把单子交给里面的师傅，然后师傅按照主食、辅食、饮料的顺序把食物放到盘子里（顺序可能有所不同，就暂且假设他们这样做吧），这其实就是一个建造者模式。

【正式的解释】

建造者模式

当面临“一个复杂对象”的创建工作，其通常由各个部分的子对象用一定的算法构成；由于需求的变化，这个复杂对象的各个部分经常面临着剧烈的变化，但是将它们组合在一起的算法确相对稳定。

【Python版】

#-*- coding:utf-8 -*-

#套餐A
class MealA(object):
    def mainFood(self):
        print "main food is ready."
    def sideFood(self):
        print "side food is ready."
    def drink(self):
        print "drink is ready."

#套餐B
class MealB(object):
    def mainFood(self):
        print "main food is ready."
    def sideFood(self):
        print "side food is ready."
    def drink(self):
        print "drink is ready."

#服务生
class Waiter(object):
    def deliver(self, meal):
        meal.mainFood()
        meal.sideFood()
        meal.drink()

if __name__ == "__main__":
    waiter = Waiter()
    waiter.deliver(MealA())

"""print out

main food is ready.
side food is ready.
drink is ready.
"""

【JS版】

//套餐A
function MealA(){
    
}
MealA.prototype = {
    mainFood: function(){
        console.log("main food is ready.");
    },
    sideFood: function(){
        console.log("side food is ready.");
    },
    drink: function(){
        console.log("drink food is ready.");
    }
}

//套餐B
function MealB(){
    
}
MealB.prototype = {
    mainFood: function(){
        console.log("main food is ready.");
    },
    sideFood: function(){
        console.log("side food is ready.");
    },
    drink: function(){
        console.log("drink food is ready.");
    }
}

//服务生
function Waiter(){

}
Waiter.prototype.deliver = function(meal){
    meal.mainFood();
    meal.sideFood();
    meal.drink();
};

waiter = new Waiter();
waiter.deliver(new MealA());

/*console out

main food is ready.
side food is ready.
drink food is ready.
*/