Number in 'Words'

README.md

README

• This ruby script converts a number to it's text form. For example, 542 is five hundred and forty two.

• Use the download button above to grab a copy.

• This requires a ruby version > 1.9

$ ruby -v  
ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin11.0.0]

• To run, first make the scripts executable.

$ cd path/to/downloaded/files/
$ chmod 777 *.rb

• And pass in a number to numtotext.rb

$ ./numtotext.rb 1234567
twelve lakh thirty four thousand five hundred and sixty seven

numtotext.rb

#!/usr/bin/env ruby

def numToText(strNum)
    ones = ["", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen"]
    tens = ["", "", "twenty", "thirty", "forty", "fifty", "sixty", "seventy", "eighty", "ninety"]
    others = ["", "", "hundred", "thousand", "lakh", "crore"]

    # Keep track of how many of each denomination make up the next larger denomination.
    # For example, 100 lakhs make a crore. Maps to the indexes of 'others'
    denomination_size = [nil, nil, 10, 100, 100, 100000]
    
    output = ""

    #Last digit
    if strNum.length == 1
        if strNum.to_i == 0 
            return "zero"
        end
        return ones[strNum.to_i]
    end
    
    #Last two digits
    if strNum[-2..-1].to_i < 20
        output = ones[strNum[-2..-1].to_i]
    else
        output = ones[strNum[-1].to_i]
        output = tens[strNum[-2].to_i] + " " + output
    end

    #All other digits
    strNum.reverse!
    i = 2
    j = 2
    while i < strNum.length

        d_length = denomination_size[j].to_s.length - 1
        d = others[j]

        if i==2 and output.length != 0
            output = "and " + output
        end

        # Recursively get the number before the denomination. For example the 'fifty' in 'fifty thousand'
        subOutput = numToText(strNum[i...i+d_length].reverse)
        
        if(subOutput != "zero" and subOutput.strip.length != 0)
             output = d + " " + output
             output = subOutput + " " + output
        end

        i = i + d_length
        j = j + 1
    end

    return output.strip
end

if ARGV.length == 1
    puts numToText ARGV[0].strip
end

numtotextTest.rb

#!/usr/bin/env ruby

require './numtotext'
require 'test/unit'

class TestNumToText < Test::Unit::TestCase
    def test_numbers
        assert_equal("twelve", numToText("12"))
        assert_equal("zero", numToText("0"))
        assert_equal("five lakh fifty thousand and forty two", numToText("550042"))
        assert_equal("one hundred", numToText("100"))
        assert_equal("twelve thousand", numToText("12000"))
        assert_equal("twelve thousand three hundred and forty five", numToText("12345"))
        assert_equal("one hundred and twenty three", numToText("123"))
        assert_equal("five hundred and four", numToText("504"))
    end
end