Enums
Enums specify a group of named numeric constants:
public enum Direction {North, East, West, South}
Unlike in C, enum members must be used with the enum type name. This resolves naming conflicts and makes code clearer:
Direction walls = Direction.East;
By default, enums are assigned integer constants 0, 1, 2, etc. You may optionally specify an alternative numeric type to base your enum and explicitly specify values for each enum member:
[Flags] public enum Direction : byte { North=1, East=2, West=4, South=8 } Direction walls = Direction.North | Direction.West; if((walls & Direction.North) != 0) System.Console.WriteLine("Can't go north!");
The [Flags]
attribute is optional and informs the
runtime that the values in the enum can be bit-combined and should be
decoded accordingly in the debugger or when outputting text to the
console. For example:
Console.WriteLine(walls); // Displays "North, West" Console.WriteLine((int) walls); // Displays "5"
The System.Enum
type also provides many useful
static methods for enums that let you determine the underlying type
of an enum, check if a specific value is supported, initialize an
enum from a string constant, retrieve a list of the valid values, and
other common operations such as conversions. Here is an example of
the usage:
using System; public enum Toggle : byte { Off=0, On=1 } class Test { static void Main( ) { Type t = Enum.GetUnderlyingType(typeof(Toggle)); Console.WriteLine(t); // Prints "Byte" bool bDimmed = Enum.IsDefined(typeof(Toggle), ...
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