Number_Pronouncer

// * Write a program that converts a number in the range
// [0...999] to a text corresponding to its English pronunciation.
// Examples:
//  0 -> "Zero"
//  273 -> "Two hundred seventy three"
//  400 -> "Four hundred"
//  501 -> "Five hundred and one"
//  711 -> "Seven hundred and eleven"


using System;

class NumberPronouncer
{
    static string GetDigit(int number) // read single digits
    {
        string strDigit = null;
        switch (number)
        {
            case 0:
                strDigit = "zero";
                break;
            case 1:
                strDigit = "one";
                break;
            case 2:
                strDigit = "two";
                break;
            case 3:
                strDigit = "three";
                break;
            case 4:
                strDigit = "four";
                break;
            case 5:
                strDigit = "five";
                break;
            case 6:
                strDigit = "six";
                break;
            case 7:
                strDigit = "seven";
                break;
            case 8:
                strDigit = "eight";
                break;
            case 9:
                strDigit = "nine";
                break;
            default:
                Console.WriteLine("Error");
                break;
        }
        return strDigit;
    }
    static string GetTen(int number) // read double digit numbers
    {
        string strTen = null;
        if (number >= 10 && number <= 19) // cases 10 to 19
        {
            switch (number)
            {
                case 10:
                    strTen = "ten";
                    break;
                case 11:
                    strTen = "eleven";
                    break;
                case 12:
                    strTen = "twelve";
                    break;
                case 13:
                    strTen = "thirteen";
                    break;
                case 14:
                    strTen = "fourteen";
                    break;
                case 15:
                    strTen = "fifteen";
                    break;
                case 16:
                    strTen = "sixteen";
                    break;
                case 17:
                    strTen = "seventeen";
                    break;
                case 18:
                    strTen = "eighteen";
                    break;
                case 19:
                    strTen = "ninteen";
                    break;
                default:
                    Console.WriteLine("error");
                    break;
            }
        }
        else // cases 20 to 99
        {
            int digit = number % 10;
            if (number >= 90 && number <= 99)
            {
                strTen = "ninety";
                if(number > 90)
                {
                    strTen += " " + GetDigit(digit);
                }
            }
            if (number >= 80 && number <= 89)
            {
                strTen = "eighty";
                if (number > 80)
                {
                    strTen += " " + GetDigit(digit);
                }
            }
            if (number >= 70 && number <= 79)
            {
                strTen = "seventy";
                if (number > 70)
                {
                    strTen += " " + GetDigit(digit);
                }
            }
            if (number >= 60 && number <= 69)
            {
                strTen = "sixty";
                if (number > 60)
                {
                    strTen += " " + GetDigit(digit);
                }
            }
            if (number >= 50 && number <= 59)
            {
                strTen = "fifty";
                if (number > 50)
                {
                    strTen += " " + GetDigit(digit);
                }
            }
            if (number >= 40 && number <= 49)
            {
                strTen = "fourty";
                if (number > 40)
                {
                    strTen += " " + GetDigit(digit);
                }
            }
            if (number >= 30 && number <= 39)
            {
                strTen = "thirty";
                if (number > 30)
                {
                    strTen += " " + GetDigit(digit);
                }
            }
            if (number >= 20 && number <= 29)
            {
                strTen = "twenty";
                if (number > 20)
                {
                    strTen += " " + GetDigit(digit);
                }
            }
        }
        return strTen;
    }
    static string GetHundred(int number) // read triple digit numbers
    {
        string strHun = null;

        int firstDigit = number / 100;
        int last2Digits = number % 100;
        strHun = GetDigit(firstDigit) + " hundred";
        if (last2Digits != 0)
        {
            if (last2Digits >= 10)
            {
                strHun += " and " + GetTen(last2Digits);
            }
            else
            {
                strHun += " and " + GetDigit(last2Digits);
            }
        }

        return strHun;
    }
    static string UppercaseFirstLetter(string s) // convert first letter of string to uppercase
    {
        if (string.IsNullOrEmpty(s))
        {
            return string.Empty;
        }
        char[] ch = s.ToCharArray();
        ch[0] = char.ToUpper(ch[0]);
        return new string(ch);
    }
    static void Main()
    {
        Console.Write("Enter a number [0...999]: ");
        string input = Console.ReadLine();

        int number = int.Parse(input);
        int copy = number;

        int numberDigits = 0;
        string pronouncedNumber = null;

        if (copy != 0)
        {
            while (copy != 0)
            {
                copy /= 10;
                numberDigits++;
            }
        }
        else
        {
            numberDigits++;
        }

        if (numberDigits == 1)
        {
            pronouncedNumber = UppercaseFirstLetter(GetDigit(number));
        }
        if (numberDigits == 2)
        {
            pronouncedNumber = UppercaseFirstLetter(GetTen(number));
        }
        if (numberDigits == 3)
        {
            pronouncedNumber = UppercaseFirstLetter(GetHundred(number));
        }

        Console.WriteLine(pronouncedNumber);

    }
}