programe

using System;
using System.Collections.Generic;
using System.Text.RegularExpressions;

namespace PersonalJournalApp
{
class PersonalJournal
{
List PersonDetails = new List();

    public class Login
    {
        public string Email { get; private set; }
        public string Password { get; private set; }

        // Μέθοδος εγγραφής νέου χρήστη
        public void Register()
        {
            Console.WriteLine("Please enter your email to register:");
            string email = Console.ReadLine();

            string emailPattern = @"^[^@\s]+@[^@\s]+\.[^@\s]+$";

            // Έλεγχος αν το email ταιριάζει με το μοτίβο
            while (!Regex.IsMatch(email, emailPattern))
            {
                Console.WriteLine("Invalid email format. Please try again:");
                email = Console.ReadLine();
            }

            Console.WriteLine("Please enter your password:");
            string password = Console.ReadLine();

            // Αποθήκευση στοιχείων μετά από επιτυχή εγγραφή
            this.Email = email;
            this.Password = password;

            Console.WriteLine("Registration successful!");
        }
    }

    public static void Main(string[] args)
    {
        Console.WriteLine("\nWelcome to your personal private Journal");

        Login login = new Login();
        login.Register();

        Console.WriteLine("\nRegistration complete. You have successfully registered with the email: " + login.Email);
//κσλεσε τις αλλες κλασεις

        Console.ReadKey();
    }
}
}

calendar

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Data.SqlTypes;
using System.Linq;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Threading.Tasks;

namespace CcharpAskiseis
{
    public class calendar
    {
        string[] monthsofAyear = { "January", "February", "March", "April", "May", "June", "July", "August",
                "September", "October", "November", "December" };
        string[] daysOfTheWeek = { "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday", "Sunday" };

        public void monthlyCalendar()
        {
            string[,] myArray = new string[2, 12]
            {
                    { "January", "February", "March", "April", "May", "June", "July", "August",
                    "September", "October", "November", "December" },

                    { "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun", "Mon", "Tue", "Wed", "Thu", "Fri" }
            };

            for (int rows = 0; rows < myArray.GetLength(0); rows++)
            {
                for (int columns = 0; columns < myArray.GetLength(1); columns++)
                {
                    Console.Write(myArray[rows, columns] + "\t");
                }
                Console.WriteLine();
            }
        }
    }
}










//    for (int k = 0; k < daysInAMonth.Length; k++)
//    {
//        Console.WriteLine(daysInAMonth[k]);
//    }

//    if (monthsofAyear[i] == "February")
//    {
//        for (int d = 0; d < 28; d++)
//        {
//            Console.WriteLine(daysInAMonth[d]);
//        }
//    }
//    else if (monthsofAyear[i] == "April" || monthsofAyear[i] == "June" || monthsofAyear[i] == "September" || monthsofAyear[i] == "November")
//    {
//        for (int m = 0; m < 30; m++)
//        {
//            Console.WriteLine(daysInAMonth[m]);
//        }
//    }
//    else
//    {
//        for (int e = 0; e < 31; e++)
//        {
//            Console.WriteLine(daysInAMonth[e]);
//        }
//    }

//}
//foreach (string day in monthsofAyear)
//{
//    Console.WriteLine(day);
//}