Learning Path Details

using System;
using System.Collections.Generic;

using GuestBookLibrary.Models;

namespace ConsoleUI
{
	internal class Program
	{
		private static void Main()
		{
			List<GuestModel> guestlist = new List<GuestModel>();

			GetGuestInformation(guestlist);

			PrintOutGuestList(guestlist);

			_ = Console.ReadLine();
		}

		private static void PrintOutGuestList(List<GuestModel> guests)
		{
			foreach ( GuestModel guest in guests )
			{
				Console.WriteLine(guest.GuestMessage);
			}
		}

		private static void GetGuestInformation(List<GuestModel> guests)
		{
			string moreguestcoming;

			do
			{
				bool isagevalid;
				GuestModel guest = new GuestModel
				{
					FirstName = GetInfoFromConsole("What is your first name: "),
					LastName = GetInfoFromConsole("What is your last name: ")
				};

				do
				{
					string agetext = GetInfoFromConsole("How old are you: ");
					isagevalid = int.TryParse(agetext, out int agenumber);
					if ( !isagevalid )
					{
						Console.WriteLine("Please enter your age as a number.");
					}

					guest.Age = agenumber;
				} while ( !isagevalid );

				guest.Hometown = GetInfoFromConsole("What is your hometowm: ");
				guest.MessageToHost = GetInfoFromConsole("What is your message for the host: ");

				guests.Add(guest);

				moreguestcoming = GetInfoFromConsole("Are more guest coming (yes/no): ");

				Console.Clear();

			} while ( moreguestcoming.ToLower() == "yes" );
		}

		private static string GetInfoFromConsole(string message)
		{
			string output;

			Console.Write(message);
			output = Console.ReadLine();

			return output;
		}
	}
}

namespace DemoLibrary
{
	public class PersonModel
	{
		public string FirstName
		{
			get; set;
		}
		public string LastName
		{
			get; set;
		}
		public string FullName
		{
			get
			{
				return $"{FirstName} {LastName}";
			}
		}
	}
}

using System;

using ConsoleUI.Models;
using ConsoleUI.UserInteraction;

namespace ConsoleUI
{
	internal class Program
	{
		private static void Main()
		{
			PersonModel person = new PersonModel
			{
				FirstName = "Tim",
				LastName = "Corey"
			};

			Messages.GreetPerson(person);

			_ = Console.ReadLine();
		}
	}
}

namespace ConsoleUI
{
	internal class AddressModel
	{
		internal string StreetAddress
		{
			get; set;
		}
		internal string City
		{
			get; set;
		}
		internal string State
		{
			get; set;
		}
		internal string ZipCode
		{
			get; set;
		}
		internal string FullAddress
		{
			get
			{
				return $"{StreetAddress}, {City} {State} {ZipCode}";
			}
		}
		internal AddressModel()
		{
		}
		internal AddressModel(string streetAddress, string city, string state, string zipCode)
		{
			StreetAddress = streetAddress;
			City = city;
			State = state;
			ZipCode = zipCode;
		}
	}
}

namespace ConsoleUI
{
	internal class PersonModel
	{
		internal string FirstName
		{
			get; set;
		}
		internal string LastName
		{
			get; set;
		}
		internal AddressModel Address
		{
			get; set;
		}
	}

	internal class AddressModel
	{
		internal string StreetAddress
		{
			get; set;
		}
		internal string City
		{
			get; set;
		}
		internal string State
		{
			get; set;
		}
		internal string ZipCode
		{
			get; set;
		}
	}
}

namespace ConsoleUI
{
	internal static class CalculateData
	{
		internal static double Operate(double x, double y, char opp)
		{
			double output = 0.0;

			switch ( opp )
			{
				case '+':
					output = Add(x, y);
					break;
				case '-':
					output = Subtract(x, y);
					break;
				case '*':
					output = Multiply(x, y);
					break;
				case '/':
					output = Divide(x, y);
					break;
				default:
					UserMessages.DisplayErrorMessage("That is not a valid operation.");
					break;
			}

			return output;
		}

		private static double Add(double x, double y)
		{
			double output = x + y;
			return output;
		}

		private static double Subtract(double x, double y)
		{
			double output = x - y;
			return output;
		}

		private static double Multiply(double x, double y)
		{
			double output = x * y;
			return output;
		}

		private static double Divide(double x, double y)
		{
			double output = 0.0;

			if ( y != 0.0 )
			{
				output = x / y;
			}
			else
			{
				UserMessages.DisplayErrorMessage("We cannot divide by zero.");
			}

			return output;
		}
	}
}