Integer to Numeral

Introduction

This code snippet will convert any integer (32-bit sized) into its numeral value (string).

Example: 1 returns "one". 2356 returns "two thousand three hundred and fifty-six". -2147483647 returns "minus two billion one hundred and forty-seven million four hundred and eighty-three thousand six hundred and forty-seven"

Using the code 

//--Use
//public static string IntToNum( int i )
//
//Ex:
//
using Numerals;

namespace SomeNamespace
{
    class SomeClass
    {
        string s = Numeral.IntToNum( 5691 );
    }
}

using System;

namespace Numerals
{
    public class Numeral
    {
        private static string Base(int i)
        {
            switch (i)
            {
                case 0: return "zero";
                case 1: return "one";
                case 2: return "two";
                case 3: return "three";
                case 4: return "four";
                case 5: return "five";
                case 6: return "six";
                case 7: return "seven";
                case 8: return "eight";
                case 9: return "nine";
                case 10: return "ten";
                case 11: return "eleven";
                case 12: return "twelve";
                case 13: return "thirteen";
                case 14: return "fourteen";
                case 15: return "fifteen";
                case 16: return "sixteen";
                case 17: return "seventeen";
                case 18: return "eighteen";
                case 19: return "nineteen";
                case 20: return "twenty";
                case 30: return "thirty";
                case 40: return "forty";
                case 50: return "fifty";
                case 60: return "sixty";
                case 70: return "seventy";
                case 80: return "eighty";
                case 90: return "ninety";
                case 100: return "hundred";
                case 1000: return "thousand";
                case 1000000: return "million";
                case 1000000000: return "billion";
            }
            return "";
        }
        //================================================================
        public static string IntToNum(int number)
        {
            if (number >= 0)
            {
                //Billion
                if (number >= 1000000000)
                {
                    int round = number / 1000000000;
                    if (number - (round * 1000000000) != 0)
                        return IntToNum(round) + " " + Base(1000000000) + " " + IntToNum(number - (round * 1000000000));
                    else
                        return IntToNum(round) + " " + Base(1000000000);
                }

                //Million
                if (number >= 1000000)
                {
                    int round = number / 1000000;
                    if (number - (round * 1000000) != 0)
                        return IntToNum(round) + " " + Base(1000000) + " " + IntToNum(number - (round * 1000000));
                    else
                        return IntToNum(round) + " " + Base(1000000);
                }

                //Ten thousand
                if (number >= 10000)
                {
                    int round = number / 1000;
                    if (number - (round * 1000) != 0)
                        return IntToNum(round) + " " + Base(1000) + " " + IntToNum(number - (round * 1000));
                    else
                        return IntToNum(round) + " " + Base(1000);
                }

                //Thousand
                if (number >= 1000)
                {
                    int round = number / 1000;
                    if (number - (round * 1000) != 0)
                        return Base(round) + " " + Base(1000) + " " + IntToNum(number - (round * 1000));
                    else
                        return Base(round) + " " + Base(1000);
                }

                //Hundred
                if (number >= 100)
                {
                    int round = number / 100;
                    if (number - (round * 100) != 0)
                        return Base(round) + " " + Base(100) + " and " + IntToNum(number - (round * 100));
                    else
                        return Base(round) + " " + Base(100);
                }

                //Over twenty
                if (number > 20)
                {
                    int round = number / 10;
                    if (number - (round * 10) != 0)
                        return Base(round * 10) + "-" + Base(number - (round * 10));
                    else
                        return Base(round * 10);
                }

                //Less than twenty
                if (number <= 20) return Base(number);
            }
            else if (number < 0)
                return "minus " + IntToNum(Math.Abs(number));
            return "";
        }
        //================================================================
    }
}

Points of Interest

One of my first projects Programming is fun ^^. I guess I could use a loop in IntToNum() to make it faster, but that's for later.

History

1.0 (14th May 2012) - Initial release.