Stephens' C# Programming with Visual Studio® 2010 24-Hour Trainer

Using Enumerations

and Structures

The data types you’ve learned about so far hold strings, integers, dates, and other pre-

defined kinds of information, but sometimes it would be nice to define your own data

types. Enumerations let you define a data type that can hold only certain values. For

example, a menu program might define a

MealType data type that can hold the values

Breakfast, Lunch, and Dinner.

The data types described in previous lessons also can hold only a single piece of data: a name,

address, date, or whatever. Sometimes it would be nice to keep related pieces of data together.

Instead of storing a name, address, and phone number in separate strings, you might like to

store them as a single unit.

Enumerations and structures let you do these things. An enumeration (or enumerated type) lets

you define a new data type that can take only one of an allowed list of values. A structure lets you

define a group of related pieces of data that should be kept together.

In this lesson, you learn how to define and use enumerations and structures to make your code

easier to understand and debug.

ENUMERATIONS

An enumeration is simply a data type that allows only specific values. The following code defines

a

ContactMethod enumeration that can hold the values None, Email, Phone, or SnailMail:

// Define possible contact methods.

enum ContactMethod

{

None = 0,

Email,

Phone,

SnailMail,

}

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