using System;

​

public class Address

{

    public string name;

    public string address;

}

​

public class MethodParams

{

    public static void Main()

    {

        string myChoice;

​

        MethodParams mp = new MethodParams();

​

        do

       {

            // show menu and get input from user

            myChoice = mp.getChoice();

​

            // Make a decision based on the user's choice

            mp.makeDecision(myChoice);

​

            // Pause to allow the user to see the results

            Console.Write("press Enter key to continue...");

            Console.ReadLine();

            Console.WriteLine();

        } while (myChoice != "Q" && myChoice != "q"); // Keep going until the user wants to quit

    }

​

    // show menu and get user's choice

    string getChoice()

    {

        string myChoice;

​

        // Print A Menu

        Console.WriteLine("My Address Book\n");

​

        Console.WriteLine("A - Add New Address");

        Console.WriteLine("D - Delete Address");

        Console.WriteLine("M - Modify Address");

        Console.WriteLine("V - View Addresses");

        Console.WriteLine("Q - Quit\n");

​

        Console.WriteLine("Choice (A,D,M,V,or Q): ");

​

        // Retrieve the user's choice

        myChoice = Console.ReadLine();

​

        return myChoice; 

    }

​

    // make decision

    void makeDecision(string myChoice)

    {

        Address addr = new Address();

​

        switch(myChoice)

        {

            case "A":

            case "a":

                addr.name = "Joe";

                addr.address = "C# Station";

                this.addAddress(ref addr);

                break;

            case "D":

            case "d":

                addr.name = "Robert";

                this.deleteAddress(addr.name);

                break;

            case "M":

            case "m":

                addr.name = "Matt";

                this.modifyAddress(out addr);

                Console.WriteLine("Name is now {0}.", addr.name);

                break;

            case "V":

            case "v":

                this.viewAddresses("Cheryl", "Joe", "Matt", "Robert");

                break;

            case "Q":

            case "q":

                Console.WriteLine("Bye.");

                break;

            default:

                Console.WriteLine("{0} is not a valid choice", myChoice);

                break;

        }

    }

​

    // insert an address

    void addAddress(ref Address addr)

    {

        Console.WriteLine("Name: {0}, Address: {1} added.", addr.name, addr.address); 

    }

​

    // remove an address

    void deleteAddress(string name)

    {

        Console.WriteLine("You wish to delete {0}'s address.", name); 

    }

​

    // change an address

    void modifyAddress(out Address addr)

    {

        //Console.WriteLine("Name: {0}.", addr.name); // causes error!

        addr = new Address();

        addr.name = "Joe";

        addr.address = "C# Station";

    }

​

    // show addresses

    void viewAddresses(params string[] names)

    {

        foreach (string name in names)

        {

            Console.WriteLine("Name: {0}", name);

        }

    }

}