public static void Main()
static void ProgramIntroduction()
Console.WriteLine("program is a credit card number validator and generator, enter your credit card number");
static string GetCreditCardNumber()
Console.WriteLine("Credit Card Validator and Generator");
return Console.ReadLine();
static void ValidateCCNumber(string number)
int[] digits = new int[number.Length];
for (int i = 0; i < digits.Length; i++)
if (int.TryParse(number.Substring(i, 1), out digits[i]) == false)
static int CalculateLuhnSum(int[] digits)
for (int i = digits.Length - 2; i>=0 ; i=i-2)
for (int i = 0; i<digits.Length; i