C# Way of the concept of OOP?

Question

Hi,

I finished the C# Objects course few days ago and now I'm working on the Address Book assignment the teacher gives in the last video to practice the OOP concept.

Now I have the feeling that I'm not doing it right and would love if someone would tell me if I'm doing it right or if I'm missing something.

So far the program ask for informations and then save it in a .txt file, but I don't feel like creating a Search the file function right now if I'm doing it "wrong" :-P

Program.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AddressBook
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Welcome to your personal 'Address Book'.");
            Console.WriteLine("\nHere is a quick instruction how to use the 'Address Book':");
            Information.Instructions();

            while (true)
            {
                Console.Write("\nPlease enter your instruction: ");
                var input = Console.ReadLine();

                if(input.ToLower() == "quit")
                {
                    break;
                }
                else if(input.ToLower() == "help")
                {
                    Information.Instructions();
                }
                else if(input.ToLower() == "new")
                {
                    Console.Clear();
                    Information.AddNewPerson();

                    while (true)
                    {
                        Console.Write("Do you want to save this? (yes/no) ");
                        var saveIt = Console.ReadLine();
                        if (saveIt.ToLower() == "no")
                        {
                            Console.Clear();
                            Information.Instructions();
                            break;
                        }
                        else if (saveIt.ToLower() == "yes")
                        {
                            // Save the information in a text file
                            SaveInfo.PrintMessage();
                            Console.Clear();
                            Console.WriteLine("The information is saved.\n");
                            Information.Instructions();
                            break;
                        }
                        else
                        {
                            Console.WriteLine("Please answer 'yes' or 'no'.");
                            continue;
                        }
                    }
                }
                else
                {
                    Console.WriteLine("That was not a valid instruction (type 'help' to get the list of instructions)");
                }
            }
        }
    }
}

Information.cs

using System;
using System.IO;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace AddressBook
{
    class Information
    {
        public static string[] info = new string[5];

        public static readonly string _path = @"AddressBook.txt";

        public static void Instructions()
        {
            Console.WriteLine("Type 'new' to add a new person to your 'Address Book'.");
            Console.WriteLine("Type 'quit' to exit the program.");
            Console.WriteLine("Type 'help' to get the instructions again.");
        }

        public static void AddNewPerson()
        {
            Console.Write("First Name: ");
            info[0] = "\nFirst name: " + Console.ReadLine();

            Console.Write("Last Name: ");
            info[1] = "Last name: " + Console.ReadLine();

            Console.Write("Address: ");
            info[2] = "Address: " + Console.ReadLine();

            while (true)
            {
                Console.Write("Phone Number: ");
                try
                {
                    var number = int.Parse(Console.ReadLine());
                    info[3] = "Phone number: " + number;
                    break;
                }
                catch(FormatException)
                {
                    Console.WriteLine("A phone number can only contain numbers");
                    continue;
                }
                catch(OverflowException)
                {
                    Console.WriteLine("The number is too long.");
                    continue;
                }
            }

            Console.Write("Email: ");
            info[4] = "Email: " + Console.ReadLine();

            for (int i = 0; i < info.Length; i++)
            {
                Console.WriteLine(info[i]);
            }
        }
    }
}

SaveInfo.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;

namespace AddressBook
{
    class SaveInfo
    {
        private static void LoopInfo(StreamWriter SW)
        {
            for (int i = 0; i < Information.info.Length; i++)
            {
                SW.WriteLine(Information.info[i]);
            }

            SW.WriteLine(); // Added to make a blank line before the new person is added to the file
            SW.Close();
        }

        public static void PrintMessage()
        {
            if (!File.Exists(Information._path))
            {
                using (StreamWriter SW = new StreamWriter(Information._path))
                {
                    LoopInfo(SW);
                }
            }
            else
            {
                using (StreamWriter SW = File.AppendText(Information._path))
                {
                    LoopInfo(SW);
                }
            }
        }
    }
}

Answer 1 · 2016-11-29T19:43:46Z

November 29, 2016 7:43pm

Henrik,

This is looking great so far! Nice job digging in and making it work :)

For more of an OOP approach, what if you were to replace the array of strings (that you're using to store the address information in) with an "Address" class? Give that a try and see where that leads you next.

Thanks ~James

Answer 2 · 2016-12-01T00:15:02Z

December 1, 2016 12:15am

Henrik,

How about an example of using class properties instead of an array to store values?

// This is a shortened version of your current Person class.
class Person
{
    // 0 = First Name
    // 1 = Last Name
    // 2 = Address
    // 3 = Phone Number
    // 4 = Email
    public string[] Info;

    public Person()
    {
        Info = new string[5];
    }
}

// This is a modified version of your Person class that replaces the array of strings with properties.
class Person
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    ...
}

I added the first two properties to get you started. Once you finish adding the other properties, your other code will break. You'll need to go through your application and update it to use your new properties instead of the array of strings.

Thanks ~James

Answer 3 · 2016-12-01T17:44:40Z

December 1, 2016 5:44pm

Hi James,

That might be a better approach. I will give it a try and see if I can make it work! :-)

Thank you very much! :-D

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Henrik Christensen

Henrik Christensen

C# Way of the concept of OOP?

3 Answers

James Churchill

James Churchill

Henrik Christensen

Henrik Christensen

James Churchill

James Churchill

Henrik Christensen

Henrik Christensen