>Hi,
>Neat recursion! I wonder if using a StringBuilder might be quicker (also making the arrays static):

 public static class NTW
>    {
>        private static readonly string[] s1 ={"One ", "Two ", "Three ", "Four ", "Five ", "Six ", "Seven ", "Eight ", 
>                                        "Nine ", "Ten ", "Eleven ", "Twelve ", "Thirteen ", "Fourteen ", "Fifteen ", "Sixteen ", 
>                                        "Seventeen ", "Eighteen ", "Nineteen "};
>
>        private static readonly string[] s2 = {"Twenty ", "Thirty ", "Forty ", "Fifty ", "Sixty ", "Seventy ", 
>                                        "Eighty ", "Ninety "};
>
>        //Wrapper class for NumberToText(int n) to account for single zero parameter.
>        public static string ConvertToStringRepresentation(long number)
>        {
>            string result = null;
>            if (number == 0)
>            {
>                result = "Zero";
>            }
>            else
>            {
>                StringBuilder sb = new StringBuilder();
>                NumberToText(number, ref sb);
>                result = sb.ToString();
>            }
>            return result;
>        }
>
>        private static void NumberToText(long n, ref StringBuilder sb)
>        {
>            if (n < 0)
>            {
>                sb.Append("Minus "); NumberToText(-n, ref sb);
>            }
>            else if (n <= 19)
>                sb.Append(s1[n - 1] );
>            else if (n <= 99)
>            {
>                sb.Append(s2[n / 10 - 2] );
>                NumberToText(n % 10, ref sb);
>            }
>            else if (n <= 199)
>            {
>                sb.Append("One Hundred ");
>                NumberToText(n % 100, ref sb);
>            }
>            else if (n <= 999)
>            {
>                NumberToText(n / 100, ref sb);
>                sb.Append("Hundred ");
>                NumberToText(n % 100, ref sb);
>            }
>            else if (n <= 1999)
>            {
>                sb.Append("One Thousand ");
>                NumberToText(n % 1000, ref sb);
>            }
>            else if (n <= 999999)
>            {
>                NumberToText(n / 1000, ref sb);
>                sb.Append("Thousand ");
>                NumberToText(n % 1000, ref sb);
>            }
>            else if (n <= 1999999)
>            {
>                sb.Append("One Million ");
>                NumberToText(n % 1000000, ref sb);
>            }
>            else if (n <= 999999999)
>            {
>                NumberToText(n / 1000000, ref sb);
>                sb.Append("Million ");
>                NumberToText(n % 1000000, ref sb);
>            }
>            else if (n <= 1999999999)
>            {
>                sb.Append("One Billion ");
>                NumberToText(n % 1000000000, ref sb);
>            }
>            else
>            {
>                NumberToText(n / 1000000000, ref sb);
>                sb.Append("Billion ");
>                NumberToText(n % 1000000000, ref sb);
>            }
>        }
>    }

Also be nice to put an "and" after the "Hundred" where ness.....
>Best,
>Viv

Viv,


I think that the use of a StringBuilder is a good idea - also making the arrays static

You do not really need to pass sb by reference, do you ?

Do you know in which cases one puts an 'and' between Hundred and what follows ?

Also, a good candidate for an extension method, I think