Question

好的，我正在学习ruby，我在教程中遇到了一些麻烦。我想知道你是否可以帮助我！

请使用以下代码：

class Dish
def initialize(name, ingred, descrip)
    @name = name
    @ingred = ingred
    @descrip = descrip
end
def name
    @name
end
def name=(new_name)
    @name = new_name
end
def ingred
    @ingred
end
def ingred=(new_ingred)
    @ingred = new_ingred
end
def descrip
    @descrip
end
def descrip=(new_descrip)
    @descrip = new_descrip
end
def display  
    puts "I am a #{@name} and my ingredient is #{@ingred} and my description is #{descrip}"  
    end
end
dis1 = Dish.new('Pizza', 'sauce', 'put sauce on that thing')
dis1.display

好的，这是我的问题，我希望我能够解释得很清楚。到目前为止，我已经学会了在创建一个类的新实例时输入一个参数（即（name，ingred，descrip））。我想知道的是，如果一道菜有多种成分，我该如何将它添加到我的班级？此外，如果我想计算成分的数量或名称的数量，我该怎么做。我只是在学习课程，而且我无法匹配谷歌的确切措辞。谢谢！

Answer 1

我会尝试回答你的一些问题。为简化起见，我删除了您的变量descrip及其相关方法。您看到我在* ingred前面放了一个initialize。这意味着在name之后传递可变数量的参数。这是处理有关多种成分的问题的一种方法。这里ingred是一个数组。由于@ingred设置为ingred，@ingred也是一个数组。如果您查看各种方法以及调用时打印的内容（如下所示），您应该能够看到它是如何工作的。（编辑添加了一些功能。您可能需要在底部向下滚动。）

class Dish
  def initialize(name, *ingred)
    @name = name
    @ingred = ingred
  end
  def name
    @name
  end
  def name=(new_name)
    @name = new_name
  end
  def ingred
    @ingred
  end
  def ingred=(*ingred)
    @ingred = ingred
  end
  def add_ingred(ingred)
    @ingred << ingred
  end  
  def remove_ingred(ingred)
    @ingred.delete(ingred)
  end  
  def nbr_ingred
    @ingred.count
  end
end

dis1 = Dish.new("Pizza", "sauce", "crust", "cheese", "anchovies")
p dis1.ingred #=> ["sauce", "crust", "cheese", "anchovies"]
dis1.add_ingred("olives")
p dis1.ingred #=> ["sauce", "crust", "cheese", "anchovies", "olives"]
dis1.add_ingred(["capers", "mushrooms"])
p dis1.ingred #=> ["sauce", "crust", "cheese", "anchovies", "olives", ["capers", "mushrooms"]]
dis1.ingred.flatten!
p dis1.ingred #=> ["sauce", "crust", "cheese", "anchovies", "olives", "capers", "mushrooms"]
dis1.remove_ingred("anchovies")
p dis1.ingred #=> ["sauce", "crust", "cheese", "olives", "capers", "mushrooms"]
p dis1.nbr_ingred #=> 6
dis1.ingred = "olives", "pineapple" # treated as ["olives", "pineapple"]
p dis1.ingred #=> [["olives", "pineapple"]]
dis1.ingred = ["cheese", "crust"]
p dis1.ingred #=> [["olives", "pineapple"]]
dis1.ingred.flatten!
p dis1.ingred #=> ["olives", "pineapple"]

Answer 2

使用数组。

class Dish
    class Ingredient
        attr_accessor :name, :description

        def initialize(name, description)
            @name = name
            @description = description
        end

        def to_s
            "#{name} - #{description}"
        end
    end

    attr_accessor :name, :description, :ingredients

    def initialize(name, description)
        @name = name
        @description = description
        @ingredients = []
    end

    def to_s
        "#{name} - #{description}\n #{ingredients.join("\n").to_s}"
    end
end

pizza = Dish.new("Pizza", "Italian style pizza")
pizza.ingredients << Dish::Ingredient.new("Tomato Sauce", "Juicy Juicy Tomato Sauce.")
pizza.ingredients << Dish::Ingredient.new("Cheese", "Cheese, duh.")

puts pizza.to_s

Answer 3

由于我之前的两个答案都没有留下描述参数，我将窃取Carry Swoveland的回答并添加描述参数：

class Dish
  attr_accessor :name, :descrip
  def initialize(name, *ingred, descrip) # Only in Ruby 1.9+
      @name = name
      @ingred = *ingred
      @descrip = descrip
  end
  def ingred
    @ingred
  end
  def ingred=(*ingred)
    @ingred = ingred
  end
  def add_ingred(ingred)
    @ingred << ingred
  end  
  def remove_ingred(ingred)
    @ingred.delete(ingred)
  end  
  def nbr_ingred
    @ingred.count
  end
  def display  
      puts "I am a #{@name} and my ingredient is #{@ingred.join(', ')} and my description is #{descrip}"  
  end
end

dis1 = Dish.new('Pizza', 'sauce', 'ham', 'put ingredients on that thing.')
dis1.add_ingred('fish')
dis1.display #=> I am a Pizza and my ingredient is sauce, ham, fish and my description is put ingredients on that thing.

Ruby中的类 - 创建将接受多个输入的参数

3 个答案: