numbers => words

in_words.rb

class Fixnum
  def in_words
    one_nineteen = {"one" => "1", "two" => "2", "three" => "3", "four" => "4", "five" => "5", "six" => "6", "seven" => "7", "eight" => "8", "nine" => "9", "ten" => "10", "eleven" => "11", "twelve" => "12", "thirteen" => "13", "fourteen" => "14", "fifteen" => "15", "sixteen" => "16", "seventeen" => "17", "eighteen" => "18", "nineteen" => "19"}
    tens = {"twenty" => "2", "thirty" => "3", "fourty" => "4", "fifty" => "5", "sixty" => "6", "seventy" => "7", "eighty" => "8", "ninty" => "9"}      
    big_nums = [" hundred ", " thousand ", " million ", " billion ", " trillion "]
    
    arrays = self.to_s.split(//) 

    arrayi = arrays.map {|e| e.to_i} 
    arrayi = arrayi.join

    if self < 20 
      array1 = self.to_s #split number into a string
      one_nineteen.key(array1) 
      elsif self < 100
        array2 = self.to_s.split(//)  
        tens.key(array2[0]) + " " + one_nineteen.key(array2[1])
      elsif self < 1000
        array3 = self.to_s.split(//) 
        one_nineteen.key(array3[0]) + big_nums.fetch(0) + tens.key(array3[1]) + " " + one_nineteen.key(array3[2])
      elsif self < 10000
       array4 = self.to_s.split(//) 
       array4[0].to_i.in_words + big_nums.fetch(1) + arrayi[1..arrays.length].to_i.in_words 
      elsif self < 20000
       array4b = self.to_s.split(//)
       array4b[0..1].join("").to_i.in_words + big_nums.fetch(1) + arrayi[2..arrays.length].to_i.in_words 
     elsif self < 100000
       array5 = self.to_s.split(//)
       array5[0..1].join("").to_i.in_words + big_nums.fetch(1) + arrayi[2..arrays.length].to_i.in_words 
     elsif self < 1000000 # 1 million
      array6 = self.to_s.split(//)
      array6[0].to_i.in_words + big_nums.fetch(0) + arrayi[1..arrays.length].to_i.in_words 
     elsif self < 10000000 # 10 million
      array7 = self.to_s.split(//)
      array7[0].to_i.in_words + big_nums.fetch(2) + arrayi[1..arrays.length].to_i.in_words 
     elsif self < 20000000 # 20 million
      array8 = self.to_s.split(//)
      array8[0..1].join("").to_i.in_words + big_nums.fetch(2) + arrayi[2..arrays.length].to_i.in_words 
     elsif self < 100000000 # 100 million
      array9 = self.to_s.split(//)
      array9[0..1].join("").to_i.in_words + big_nums.fetch(2) + arrayi[2..arrays.length].to_i.in_words 
     elsif self < 1000000000 # 1 billion
      array10 = self.to_s.split(//)
      array10[0].to_i.in_words + big_nums.fetch(0) + arrayi[1..arrays.length].to_i.in_words 
     elsif self < 10000000000 # 10 billion
      array11 = self.to_s.split(//)
      array11[0].to_i.in_words + big_nums.fetch(3) + arrayi[1..arrays.length].to_i.in_words 
     elsif self < 20000000000 # 20 billion
      array12 = self.to_s.split(//)
      array12[0..1].join("").to_i.in_words + big_nums.fetch(3) + arrayi[2..arrays.length].to_i.in_words 
     elsif self < 100000000000 # 100 billion
      array13 = self.to_s.split(//)
      array13[0..1].join("").to_i.in_words + big_nums.fetch(3) + arrayi[2..arrays.length].to_i.in_words
     elsif self < 1000000000000 # 1 trillion
      array14 = self.to_s.split(//)
      array14[0].to_i.in_words + big_nums.fetch(0) + arrayi[1..arrays.length].to_i.in_words
     elsif self < 10000000000000 # 10 trillion
      array15 = self.to_s.split(//)
      array15[0].to_i.in_words + big_nums.fetch(4) + arrayi[1..arrays.length].to_i.in_words
    end 
  end
end 

puts "'#{8.in_words}' should equal 'eight'"
puts "'#{18.in_words}' should equal 'eighteen'"
puts "'#{36.in_words}' should equal 'thirty six'"
puts "'#{459.in_words}' should equal 'four hundred fifty nine'"
puts "'#{999.in_words}' should equal 'nine hundred ninety nine'"
puts "'#{4489.in_words}' should equal 'four thousand four hundred eighty nine'"
puts "'#{19999.in_words}' should equal 'nineteen thousand nine hundred ninety nine'"
puts "'#{88888.in_words}' should equal 'eighty thousand eight hundred eighty eight'"
puts "'#{123456.in_words}' should equal 'one hundred twenty three thousand four hundred fifty six'"
puts "'#{1234567.in_words}' should equal 'one million two hundred thirty four thousand five hundred sixty seven'"
puts "'#{12345678.in_words}' should equal 'twelve million three hundred forty five thousand six hundred seventy eight'"
puts "'#{987654321.in_words}' should equal 'nine hundred eighty seven million six hundred fifty four thousand three hundred twenty one'"
puts "'#{4567893123.in_words}' should equal 'four billion five hundred sixty seven million eight hundred ninety three thousand one hundred twenty three'"
puts "'#{87654321197.in_words}' should equal 'eighty seven billion six hundred fifty four million three hundred twenty one thousand one hundred ninty seven'"
puts "'#{999999999999.in_words}' should equal 'nine hundred ninty nine billion nine hundred ninty nine million nine hundred ninty nine thousand nine hundred ninty nine'"
puts "'#{2346456433118.in_words}' should equal 'two trillion three hundred forty six billion f hundred fifty six million four hundred thirty three thousand one hundred eighteen'"