Number to English Number

gistfile1.rb

#Returns a number in english language

def english_number (number)

  raise ArgumentError.new("Argument must be a positive integer") if !(number.is_a? Integer) || number < 0 

  return 'zero' if number == 0

  result = ""

  text_version = {
  'trillion'  => 1000000000000,
  'billion'   => 1000000000,
  'million'   => 1000000,
  'thousand'  => 1000,
  'hundred'   => 100,
  'ninety'  => 90,
  'eighty'  => 80,
  'seventy'   => 70,
  'sixty'   => 60,
  'fifty'   => 50,
  'fourty'  => 40,
  'thirty'  => 30,
  'twenty'  => 20,
  'nineteen'  => 19,
  'eighteen'  => 18,
  'seventeen' => 17,
  'sixteen'   => 16,
  'fifteen'   => 15,
  'fourteen'  => 14,
  'thirteen'  => 13,
  'twelve'  => 12,
  'eleven'  => 11,
  'ten'     => 10,
  'nine'    => 9,
  'eight'   => 8,
  'seven'   => 7,
  'six'     => 6,
  'five'    => 5,
  'four'    => 4,
  'three'   => 3,
  'two'     => 2,
  'one'     => 1
  }

  text_version.each do |text , value|

    if number/value > 1
      result << english_number(number/value) + text + ' ' # Recursion

    elsif number/value == 1

      # result << 'one ' if number >= 100 # Adds Prefix for numbers greater 100 starting with 'one'
      result << text 
      (number < 100 && number >= 20) ? result << '-' : result << ' ' # Add sufix for numbers greater than 20 and smaller than 100   
    end

    number -= value * (number/value)
    break if number == 0
  end

  return result
end

#Tests
puts english_number(0)
puts english_number(9)
puts english_number(10)
puts english_number(11)
puts english_number(17)
puts english_number(32)
puts english_number(88)
puts english_number(99)
puts english_number(100)
puts english_number(101)
puts english_number(234)
puts english_number(3211)
puts english_number(10000)
puts english_number(999999)
puts english_number(1000000000000)