C# - enum

In C#, enum is a value type data type. The enum is used to declare a list of named integer constants. It can be defined using the enum keyword directly inside a namespace, class, or structure. The enum is used to give a name to each constant so that the constant integer can be referred using its name.

enum WeekDays
{
    Monday = 0,
    Tuesday =1,
    Wednesday = 2,
    Thursday = 3,
    Friday = 4,
    Saturday =5,
    Sunday = 6
}
Console.WriteLine(WeekDays.Friday);
Console.WriteLine((int)WeekDays.Friday);

By default, the first member of an enum has the value 0 and the value of each successive enum member is increased by 1. For example, in the following enumeration, Monday is 0, Tuesday is 1, Wednesday is 2 and so forth.

enum WeekDays
{
    Monday,
    Tuesday,
    Wednesday,
    Thursday,
    Friday,
    Saturday,
    Sunday
}
Console.WriteLine((int)WeekDays.Monday);
Console.WriteLine((int)WeekDays.Friday);

An explicit cast is necessary to convert from enum type to an integral type. For example, to get the int value from an enum:

int dayNum = (int)WeekDays.Friday;
Console.WriteLine(dayNum);

A change in the value of the first enum member will automatically assign incremental values to the other members sequentially. For example, changing the value of Monday to 10, will assign 11 to Tuesday, 12 to Wednesday, and so on:

enum WeekDays
{
    Monday = 10,
    Tuesday,
    Wednesday,
    Thursday,
    Friday,
    Saturday,
    Sunday
}
Console.WriteLine((int)WeekDays.Monday);
Console.WriteLine((int)WeekDays.Friday);

The enum can includes named constants of numeric data type e.g. byte, sbyte, short, ushort, int, uint, long, or ulong.

Enum cannot be used with string type.

Enum is mainly used to make code more readable by giving related constants a meaningful name. It also improves maintainability.

Enum methods:

Enum is an abstract class that includes static helper methods to work with enums.

enum WeekDays
{
    Monday,
    Tuesday,
    Wednesday,
    Thursday,
    Friday,
    Saturday,
    Sunday
}
Console.WriteLine(Enum.GetName(typeof(WeekDays), 4));
Console.WriteLine("WeekDays constant names:");
foreach (string str in Enum.GetNames(typeof(WeekDays)))
                        Console.WriteLine(str);
Console.WriteLine("Enum.TryParse():");
WeekDays wdEnum;
Enum.TryParse<WeekDays>("1", out wdEnum);
Console.WriteLine(wdEnum);

Visit MSDN to know more about C# enum methods.

Points to Remember :

1. The enum is a set of named constant.
2. The value of enum constants starts from 0. Enum can have value of any valid numeric type.
3. String enum is not supported in C#.
4. Use of enum makes code more readable and manageable.