"Class Warfare, Validate a Credit Card Number"

gistfile1.rb

class CreditCard
  def initialize(card_number)
    @card = card_number.to_s
    if @card.length != 16
      raise ArgumentError.new("This is not a valid credit card number.")
    end
  end
  
  def check_card
    chars = @card.split(//)
    array = chars.collect! { |x| x.to_i }
    double = array.map! { |x| x.even ? x * 2 : x }
    double = array.join
    double = array.to_s.split(//)
    double = double.collect! { |x| x.to_i }
    sum = 0
    double.each { |x| sum += x }
    sum % 10 == 0
  end
end
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#This is another iteration I've tried that doesn't seem to work either:

class CreditCard
  def initialize(card_number)
    @card = card_number.to_s
    if @card.length != 16
      raise ArgumentError.new("This is not a valid credit card number.")
    end
  end

  def check_card
    chars = @card.split(//)
    array = chars.collect! { |x| x.to_i }
    double = array.each_with_index do |item, index|
      if (index % 2 == 0)
        array << (item * 2)
      else
        item = item
      end
    end
    double = array.join
    double = array.to_s.split(//)
    double = double.collect! { |x| x.to_i }
    sum = 0
    double.each { |x| sum += x }
    sum % 10 == 0
  end
end