Get String Name from Enum in C#

Question

I have declared an enum as below:

public enum State
    {
        KARNATAKA = 1,
        GUJRAT = 2,
        ASSAM = 3,
        MAHARASHTRA = 4,
        GOA = 5
    }

From external sources, I get the State values as either 1 or 2 or 3 or 4 or 5.

Based on the value I get, I need to look up this enum and get its string.

For example: If the input value is 1, I need to return KARNATAKA as string. Similarly, if the input value is 5, I need to return GOA as a string.

Is there an easy way to get the string without using CASE or IFELSE?

Answer 1

You can simply use the nameof expression to get the name of an enum, enum value, property, method, classname, etc.

The fastest, compile time solution using nameof expression.

Returns the literal of the enum.

public enum MyEnum {
    CSV,
    Excel
}

// calling code
string enumAsString = nameof(MyEnum.CSV) // enumAsString = "CSV"

Answer 2

You can add Description tags to your enum like below:

public enum State
{
    [Description("Karnataka")]
    KARNATAKA = 1,
    [Description("Gujarat")]
    GUJRAT = 2,
    [Description("Assam")]
    ASSAM = 3,
    [Description("Maharashtra")]
    MAHARASHTRA = 4,
    [Description("Goa")]
    GOA = 5
}

And then get assigned a Description string from an enum like below:

State stateVal = State.GOA;
string stateName = GetEnumDescription(stateVal);

If you have state as in a number as you have mentioned in comments, you can still easily cast it to an enum type.

int stateVal = 2;
string stateName = GetEnumDescription((State)stateVal);

GetEnumDescription() which returns string for name of Enumerations.

public static string GetEnumDescription(Enum enumVal)
{
    System.Reflection.MemberInfo[] memInfo = enumVal.GetType().GetMember(enumVal.ToString());
    DescriptionAttribute attribute = CustomAttributeExtensions.GetCustomAttribute<DescriptionAttribute>(memInfo[0]);
    return attribute.Description;
}

NOTE

As an operation on an enum is less costly than string operations, the string value of enum should be limited to display purposes only, while internally you must use the enum itself in logic.

The way to get the string value of an enum is more preferred. As if you have used enum at a lot of places in your code, and you need to change the text on a display, you will have to change the text at one place only.

For example,

Suppose you have used this enum throughout your project and then you realize that your spelling of Gujarat is wrong. If you change the text of enum itself, you need to change it through whole code (thankfully, Visual Studio makes it a little easier) while if you use Description as a label to be displayed, you will only need to change that only.

Or

when you have a space in the name (which you have to display).

For example, "Jammu and Kashmir" is another state of India.

You can have an abbreviation (here "JK") in an enum name and complete the string with a space in the description.

Answer 3

You can write an extension class/method specific to enumerations that will get the text value. This is based off of the above approach, however, it eliminates a boilerplate code being wrapped around enums and simplifies the code required to get these names.

The benefit to this approach is that you can use this extension directly from the enum value much like using nameof(MyEnum.Value1), or you can use it on a property of an object which wouldn't work using the nameof(...) approach.

Here is the extension code:

    public static class EnumerationExtensions
    {
        public static string AsText<T>(this T value) where T : Enum
        {
            return Enum.GetName(typeof(T), value);
        }
    }

Usage:

enum MyEnum {
  Value1,
  Value2,
}

class MyObject {
  MyEnum enumValue;
}


// Output directly from an Enum value
Console.WriteLine(MyEnum.Value1.AsText());  // Output: Value1

// Output from a property that is an enumeration
// NOTE: nameof(obj.enumValue) would not provide the desired value. but the AsText() method will give the name of the property value.
new obj = new MyObject { enumValue = MyEnum.Value2 };
Console.WriteLine(obj.enumValue.AsText());  //Output: Value2

Answer 4

Here ise better solution

public static string AsString<T>(this T value) where T : Enum
{
    return Enum.GetName(typeof(T), value);
}

public static T AsEnum<T>(this int value) where T : Enum
{
    if (Enum.IsDefined(typeof(T), value))
    {
        return (T)Enum.ToObject(typeof(T), value);
    }
    else
    {
        throw new ArgumentException($"{value} is not a valid value for enum {typeof(T).Name}");
    }
}
public static int AsInt<T>(this T value) where T : Enum
{
    return (int)(object)value;
}