static void Main(string[] args) { Customer customer1, customer2, customer3; Customers(out customer1, out customer2, out customer3); CustomerManager customerManager = new CustomerManager(); int result = 0; while (result != -1) { Console.WriteLine("Select your action\n1-) Customer Add\n2-) Customer Delete\n3-)Customer List\nTo exit : -1\n"); result = Convert.ToInt32(Console.ReadLine()); switch (result) { case 1: int select; Console.WriteLine("There are 3 customers, enter the id of the customer you want to add select to(1,2or3)\n"); select = Convert.ToInt32(Console.ReadLine()); if (select == 1) { customerManager.Added(customer1); } else if (select == 2) { customerManager.Added(customer2); } else if (select == 3) { customerManager.Added(customer3); } else { Console.WriteLine("No customer with this claim found"); } break; case 2: int select2; Console.WriteLine("There are 3 customers, enter the id of the customer you want to delete select to(1,2or3)\n"); select2 = Convert.ToInt32(Console.ReadLine()); if (select2 == 1) { customerManager.Deleted(customer1); } else if (select2 == 2) { customerManager.Deleted(customer2); } else if (select2 == 3) { customerManager.Deleted(customer3); } else { Console.WriteLine("No customer with this claim found"); } break; case 3: Console.WriteLine("Customer List is \n:"); customerManager.CustomerList(customer1, customer2, customer3); break; default: break; } } }