Enumerations in C#

Enumerations are set of named constants. We can use them when we need to choose between set of constant values.

public enum DayType
{
    Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday
}

Underlying type of each element is int by default but still are allowed to assign any value to the enum list.

public enum DayType

{

    Sunday = 0, 

    Monday = 5, 

    Tuesday = 7,

    Wednesday = 8, 

    Thursday = 10, 

    Friday = 11, 

    Saturday = 13

    

}

Get the enum string representation

string str = DayType.Monday.ToString();

Result: Monday

Get the underlying values of the item

int a = (int)DayType.Monday;

Result: 5

An example to ensure an enum value exists and then parse it.

// Fake Day of Week 

string strDOWFake = "SuperDay"; 

// Real Day of Week 

string strDOWReal = "Friday"; 

// Will hold which ever is the real DOW. 

DayType enmDOW; 

 // See if fake DOW is defined in the DayOfWeek enumeration. 

if (Enum.IsDefined(typeof(DayType), strDOWFake)) 

{ 

// This will never be reached since "SuperDay"

 // doesn't exist in the DayOfWeek enumeration. 

 enmDOW = (DayType)Enum.Parse(typeof(DayType), strDOWFake); 

}

 // See if real DOW is defined in the DayOfWeek enumeration. 

else if (Enum.IsDefined(typeof(DayType), strDOWReal))

 { 

 // This will parse the string into it's corresponding DOW enum object. 

 enmDOW = (DayType)Enum.Parse(typeof(DayType), strDOWReal); 

} 

 // Can now use the DOW enum object. 

Response.Write("Today is " + enmDOW.ToString() + ".");

OutPut:
Today is Friday.

Print all string representations in enum list

string[] values = Enum.GetNames(typeof(DayType));

foreach (string s in values)
Response.Write(s+"<br/>");

OutPut:
Sunday

Monday 

Tuesday 

Wednesday  

Thursday 

Friday  

Saturday