in_words

gistfile1.txt

module InWords
  def in_words
    return "n/a" if self > 999
    num = []
    h_num = self - (self%100)
    t_num = self - h_num - (self%10)
    o_num = self - h_num - t_num - (self%1)

    h_words =   ["one", "two", "three", "four", "five", "six", "seven", "eight", "nine"]
    t_words =   ["twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety"]
    t_o_words = ["one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", 
                 "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", 
                 "eighteen", "nineteen"]
    o_words =   ["one", "two", "three", "four", "five", "six", "seven", "eight", "nine"]
    
    if h_num > 0
      # 100-900 - all hundred-digits are the same
      num << h_words[h_num/100 - 1] + " hundred"
    end
    
    if t_num > 20
      # 20-90 - all ten-digits are the same
      num << t_words[t_num/10 - 2]
    end
    
    if (t_num+o_num) < 20
      # 1-19 - all unqiue, need to just look up
      num << t_o_words[(t_num+o_num) -1]      
    else
      # 1-9
      num << o_words[o_num -1]      
    end

    num.join(" ")
  end
end

class Fixnum
  include InWords
end