Using Ruby convert numbers to words?

Question

How to convert numbers to words in ruby?

I know there is a gem somewhere. Trying to implement it without a gem. I just need the numbers to words in English for integers. Found this but it is very messy. If you have any idea on how to implement a cleaner easier to read solution please share.

http://raveendran.wordpress.com/2009/05/29/ruby-convert-number-to-english-word/

Here is what I have been working on. But having some problem implementing the scales. The code is still a mess. I hope to make it more readable when it functions properly.

   class Numberswords
    def in_words(n)

    words_hash = {0=>"zero",1=>"one",2=>"two",3=>"three",4=>"four",5=>"five",6=>"six",7=>"seven",8=>"eight",9=>"nine",
                    10=>"ten",11=>"eleven",12=>"twelve",13=>"thirteen",14=>"fourteen",15=>"fifteen",16=>"sixteen",
                     17=>"seventeen", 18=>"eighteen",19=>"nineteen",
                    20=>"twenty",30=>"thirty",40=>"forty",50=>"fifty",60=>"sixty",70=>"seventy",80=>"eighty",90=>"ninety"}

     scale = [000=>"",1000=>"thousand",1000000=>" million",1000000000=>" billion",1000000000000=>" trillion", 1000000000000000=>" quadrillion"]


    if words_hash.has_key?(n) 
      words_hash[n]

      #still working on this middle part. Anything above 999 will not work
     elsif n>= 1000  
     print  n.to_s.scan(/.{1,3}/) do |number|
            print number
      end



      #print value = n.to_s.reverse.scan(/.{1,3}/).inject([]) { |first_part,second_part| first_part << (second_part == "000" ? "" : second_part.reverse.to_i.in_words) }
      #(value.each_with_index.map { |first_part,second_part| first_part == "" ? "" : first_part + scale[second_part] }-[""]).reverse.join(" ")

    elsif n <= 99
       return [words_hash[n - n%10],words_hash[n%10]].join(" ")
    else
      words_hash.merge!({ 100=>"hundred" })
      ([(n%100 < 20 ? n%100 : n.to_s[2].to_i), n.to_s[1].to_i*10, 100, n.to_s[0].to_i]-[0]-[10])
        .reverse.map { |num| words_hash[num] }.join(" ")
    end
  end
end

#test code
test = Numberswords.new
 print test.in_words(200)

Answer 1

Simple answer use humanize gem and you will get desired output

Install it directly

gem install humanize

Or add it to your Gemfile

gem 'humanize'

And you can use it

require 'humanize'

1.humanize       #=> 'one'
345.humanize     #=> 'three hundred and forty-five'
1723323.humanize #=> 'one million, seven hundred and twenty-three thousand, three hundred and twenty-three'

If you are using this in rails you can directly use this

NOTE: As mentioned by sren in the comments below. The humanize method provided by ActiveSupport is different than the gem humanize

Answer 2

My take on this

def in_words(int)
  numbers_to_name = {
      1000000 => "million",
      1000 => "thousand",
      100 => "hundred",
      90 => "ninety",
      80 => "eighty",
      70 => "seventy",
      60 => "sixty",
      50 => "fifty",
      40 => "forty",
      30 => "thirty",
      20 => "twenty",
      19=>"nineteen",
      18=>"eighteen",
      17=>"seventeen", 
      16=>"sixteen",
      15=>"fifteen",
      14=>"fourteen",
      13=>"thirteen",              
      12=>"twelve",
      11 => "eleven",
      10 => "ten",
      9 => "nine",
      8 => "eight",
      7 => "seven",
      6 => "six",
      5 => "five",
      4 => "four",
      3 => "three",
      2 => "two",
      1 => "one"
    }
  str = ""
  numbers_to_name.each do |num, name|
    if int == 0
      return str
    elsif int.to_s.length == 1 && int/num > 0
      return str + "#{name}"      
    elsif int < 100 && int/num > 0
      return str + "#{name}" if int%num == 0
      return str + "#{name} " + in_words(int%num)
    elsif int/num > 0
      return str + in_words(int/num) + " #{name} " + in_words(int%num)
    end
  end
end



puts in_words(4) == "four"
puts in_words(27) == "twenty seven"
puts in_words(102) == "one hundred two"
puts in_words(38_079) == "thirty eight thousand seventy nine"
puts in_words(82102713) == "eighty two million one hundred two thousand seven hundred thirteen"