C# AddressBook

Address.cs

using System;

class Address {
  public string name;
  public string address;

  public Address(string name, string address) {
    this.name = name;
    this.address = address;
  }
}

AddressBook.cs

using System;
using System.Collections.Generic;


class AddressBook {
  List<Address> addresses;

  public AddressBook() {
    addresses = new List<Address>();
  }

  public bool add(string name, string address) {
    Address addr = new Address(name, address);
    Address result = find(name);

    if (result == null) {
      addresses.Add(addr);
      return true;
    } else {
      return false;
    }
  }

  public bool remove(string name) {
    Address addr = find(name);

    if (addr != null) {
      addresses.Remove(addr);
      return true;
    } else {
      return false;
    }
  }

  public void list(Action<Address> action) {
    addresses.ForEach(action);
  }

  public bool isEmpty() {
    return (addresses.Count == 0);
  }

  public Address find(string name) {
    Address addr = addresses.Find(
      delegate(Address a) {
        return a.name == name;
      }
    );
    return addr;
  }
}

Main.cs

using System;
using System.Collections.Generic;

class AddressPrompt {
  AddressBook book;

  public AddressPrompt() {
    book = new AddressBook();
  }

  static void Main(string[] args) {
    string selection = "";
    AddressPrompt prompt = new AddressPrompt();

    prompt.displayMenu();
    while (!selection.ToUpper().Equals("Q")) {
      Console.WriteLine("Selection: ");
      selection = Console.ReadLine();
      prompt.performAction(selection);
    }
  }

  void displayMenu() {
    Console.WriteLine("Main Menu");
    Console.WriteLine("=========");
    Console.WriteLine("A - Add an Address");
    Console.WriteLine("D - Delete an Address");
    Console.WriteLine("E - Edit an Address");
    Console.WriteLine("L - List All Addresses");
    Console.WriteLine("Q - Quit");
  }

  void performAction(string selection) {
    string name = "";
    string address = "";

    switch (selection.ToUpper()) {
      case "A":
        Console.WriteLine("Enter Name: ");
        name = Console.ReadLine();
        Console.WriteLine("Enter Address: ");
        address = Console.ReadLine();
        if (book.add(name, address)) {
          Console.WriteLine("Address successfully added!");
        } else {
          Console.WriteLine("An address is already on file for {0}.", name);
        }
        break;
      case "D":
        Console.WriteLine("Enter Name to Delete: ");
        name = Console.ReadLine();
        if (book.remove(name)) {
          Console.WriteLine("Address successfully removed");
        } else {
          Console.WriteLine("Address for {0} could not be found.", name);
        }
        break;
      case "L":
        if (book.isEmpty()) {
          Console.WriteLine("There are no entries.");
        } else {
          Console.WriteLine("Addresses:");
          book.list(
            delegate(Address a) {
              Console.WriteLine("{0} - {1}", a.name, a.address);
            }
          );
        }
        break;
      case "E":
        Console.WriteLine("Enter Name to Edit: ");
        name = Console.ReadLine();
        Address addr = book.find(name);
        if (addr == null) {
          Console.WriteLine("Address for {0} count not be found.", name);
        } else {
          Console.WriteLine("Enter new Address: ");
          addr.address = Console.ReadLine();
          Console.WriteLine("Address updated for {0}", name);
        }
        break;
    }
  }
}