Ruby-过敏-挑战

Question

我对Codewar编码挑战和解决方案中的以下代码有一些疑问。 我已经在编码解决方案下列出了我的问题。 提前谢谢了！

编码挑战问题如下。

An allergy test produces a single numeric score which contains the information about all the allergies the person has (that they were tested for). The list of items (and their value) that were tested are: eggs (1), peanuts (2), shellfish (4), strawberries (8), tomatoes (16), chocolate (32), pollen (64) & cats (128). So if Tom is allergic to peanuts and chocolate, he gets a score of 34. Write a program that, given a person’s score can tell them: a. whether or not they’re allergic to a given item b. the full list of allergies.

You will be provided with a class Allergies which will have 2 methods

 1. is_allergic_to Checks if Tom is allergic to a particular allergen.
    Returns True if Tom is allergic, False otherwise allergies
 2. Returns a list of what Tom is allergic to. This list must be sorted
    alphabetically
 3. Must Dos: Ensure that your function throws a TypeError for invalid
    inputs such as None(Null), floats, strings, or any data type that is
    not an integer.

以下是上述挑战的Ruby代码。

class Allergies
  ALLERGY_SCORES = {
    "eggs"=> 1,
    "peanuts"=> 2,
    "shellfish"=> 4,
    "strawberries"=> 8,
    "tomatoes"=> 16,
    "chocolate"=> 32,
    "pollen"=> 64,
    "cats"=> 128
  }

  def initialize(score)
    @score = score
  end

  def is_allergic_to(allergen)
    @score & ALLERGY_SCORES[allergen] > 0 

      begin
        @score = [/\D/]
      rescue StandardError => e
        puts "Error occured: #{e}."
        puts "Please enter integer ONLY."
      end
  end

  def allergies()
    ALLERGY_SCORES.keys.select do |allergen|
      is_allergic_to(allergen)
    end 
  end

  def acceptable_score()
    max_score = 0
    ALLERGY_SCORES.each do |allergen, score|
        max_score += score
    return max_score
  end
end

puts "Please enter allergy score or  "
score = gets.chomp 
Allergies.new.initialize(score)
Allergies.is_allergic_to
# Allergies.allergies

问题-1-哈希-＆运算符使用

在下面的方法中，过敏原被引用以从ALLERGY_SCORES过敏常数哈希中获取密钥值。 为什么@score & ALLERGY_SCORES[allergen] > 0 ？ 在ALLERGY_SCORES哈希中，只有值是整数。 为什么在其中使用＆运算符？

将@socre和ALLERGY_SCORES都设置为大于0-是否也用于验证？ （以防用户输入负值或其他值）

def is_allergic_to(allergen)
 @score & ALLERGY_SCORES[allergen] > 0 
end

问题-2-错误处理

在代码中，没有错误处理组件。 因此，我尝试解决此问题，并在is_allergic_to方法中添加了以下代码。 但是，我得到一个错误。

  def is_allergic_to(allergen)
    @score & ALLERGY_SCORES[allergen] > 0 

      **begin
        @score = [/\D/]
      rescue StandardError => e
        puts "Error occured: #{e}."
        puts "Please enter integer ONLY."
      end**
  end

问题-3-创建新的密钥数组（过敏原）

.keys方法是创建一个新数组，该数组是过敏原的列表。 .select方法也用于创建新数组。

为什么同时使用.keys和.select方法从ALLERGY_SCORES哈希创建新的键数组？

  def allergies()
    ALLERGY_SCORES.keys.select do |allergen|
      is_allergic_to(allergen)
    end 
  end

问题-4-代码显示输出到终端的屏幕

我希望用户能够输入他们的过敏评分。 但是以下代码不起作用。

puts "Please enter allergy score."
score = gets.chomp 
Allergies.new.initialize(score)
Allergies.is_allergic_to
Allergies.allergies

问题-5-最高可接受分数验证

最高可接受分数是255。如何验证分数以确保他们输入的分数小于或等于255？ 我应该如何修改这部分代码？

def acceptable_score()
    max_score = 0
    ALLERGY_SCORES.each do |allergen, score|
        max_score += score
    return max_score
  end