C# 0 The Complete Reference

Specify the Underlying Type of an Enumeration

By default, enumerations are based on type 

int

, but you can create an enumeration of any 

integral type, except for type 

char

. To specify a type other than 

int

, put the desired type 

after the enumeration name, separated by a colon. For example, this statement makes 

Apple

 an enumeration based on 

byte

:

enum Apple : byte { Jonathan, GoldenDel, RedDel, Winesap,

                    Cortland, McIntosh };

Now

Apple.Winesap

, for example, is a 

byte

 quantity.

Use Enumerations

At first glance you might think that enumerations are an interesting but relatively 

unimportant part of C#, yet this is not the case. Enumerations are very useful when your 

program requires one or more specialized symbols. For example, imagine that you are 

writing a program that controls a conveyor belt in a factory. You might create a method 

called

Conveyor( )

 that accepts the following commands as parameters: start, stop, forward, 

and reverse. Instead of passing 

Conveyor( )

 integers, such as 1 for start, 2 for stop, and so 

on, which is error-prone, you can create an enumeration that assigns words to these values. 

Here is an example of this approach:

// Simulate a conveyor belt.

using System;

class ConveyorControl {

  // Enumerate the conveyor commands.

  public enum Action { Start, Stop, Forward, Reverse };

  public void Conveyor(Action com) {

    switch(com) {

      case Action.Start:

        Console.WriteLine("Starting conveyor.");

        break;

      case Action.Stop:

        Console.WriteLine("Stopping conveyor.");

        break;

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