Question

我根据Head first Design Patterns一书制作了以下代码。

哪个代码是使用javascript修饰模式的最佳实现？

第一个和第二个代码的结果是相同的。

Fisrt示例代码与book相同的界面。

第二个与书有点不同，它分为两部分。

所以有三种选择。第一部分，第二部分1和第二部分。

我需要一个答案，其中一个是关于OOP和javascript的问题。

Thax！

＆＃13;

function DarkRoast(){
	this.description = 'Dark Roast';
  this.cost = function(){
  	return 2;
  }
  this.getDescription = function(){
  	return this.description;
  }
}

function HouseBlend(){
	this.description = 'House Blend';
  this.cost = function(){
  	return 1;
  }
  this.getDescription = function(){
  	return this.description;
  }
}

function Mocha(beverage){
	this.getDescription = function(){
  	return beverage.getDescription() + ', Mocha'
  }
  this.cost = function(){
   	return beverage.cost() + 0.5;
   }
}

function Whip(beverage){
	this.getDescription = function(){
  	return beverage.getDescription() + ', whip'
  }
  this.cost = function(){
   	return beverage.cost() + 0.7;
   }
}
// EX1
var beverage1 = new DarkRoast();
beverage1 = new Mocha(beverage1);
beverage1 = new Mocha(beverage1);
beverage1 = new Whip(beverage1);
console.log(beverage1.getDescription(),beverage1.cost());
var beverage2 = new HouseBlend();
beverage2 = new Mocha(beverage2);
beverage2 = new Whip(beverage2);
console.log(beverage2.getDescription(),beverage2.cost());

＆＃13;

function Beverage(name, cost){
	this.description = name;
  this.cost = function(){
  	return cost;
  }
  this.getDescription = function(){
  	return this.description;
  }
}
function AddSome(beverage, name, cost){
	this.getDescription = function(){
  	return beverage.getDescription() + ', ' + name;
  }
  this.cost = function(){
   	return beverage.cost() + cost;
  }
}

var darkRoast = function(){
	return new Beverage('Dark Roast',2);
}
var moch = function(beverage){
	return new AddSome(beverage, 'Mocha', 0.5);
}
var whip = function(beverage){
	return new (AddSome.bind(null, beverage, 'Whip', 0.7))();
}

// EX2 part1
var beverage1 = darkRoast();
beverage1 = moch(beverage1);
beverage1 = moch(beverage1);
beverage1 = whip(beverage1);
console.log(beverage1.getDescription(),beverage1.cost());

// EX2 part2
var beverage2 = new Beverage('House Blend',1);
beverage2 = new AddSome(beverage2, 'Mocha', 0.5);
beverage2 = new AddSome(beverage2, 'Whip', 0.7);
console.log(beverage2.getDescription(),beverage2.cost());

＆＃13;

哪个代码最好？我正在学习用javascript装饰模式

0 个答案: