6.19Loops_ConvertDecimalNumberToHexadecimalSystem

using System;
using System.Collections.Generic;

class ConvertDecimalNumberToHexadecimalSystem
{
    static void Main ()
    {
        Console.Write("Enter a whole non-negative Decimal number, DECIMAL = ");
        string numberStr = Console.ReadLine();
        ulong numDecimal = ulong.Parse(numberStr);

        List<byte> hexadecs = new List<byte>();
        ulong quotient = 0;
        byte remainder = 0;
        checked
        {
            do
            {
                quotient = numDecimal / 16;
                remainder = (byte)(numDecimal % 16);
                hexadecs.Add(remainder);
                numDecimal = quotient;
            } while (quotient != 0);
        }
        hexadecs.Reverse();
        Console.WriteLine("That Decimal number in Hexadecimal system is:");
        Console.Write("HEXADECIMAL NUMBER = 0x");
        foreach (var digit in hexadecs)
        {
            if (digit > 9)
            {
                switch (digit)
                {
                    case 10: Console.Write("A"); break;
                    case 11: Console.Write("B"); break;
                    case 12: Console.Write("C"); break;
                    case 13: Console.Write("D"); break;
                    case 14: Console.Write("E"); break;
                    case 15: Console.Write("F"); break;
                }
            }
            else
            {
                Console.Write("{0}", digit);
            }
        }
        Console.WriteLine();
        Console.ReadLine();
    }
}