convert an enum to another type of enum

Question

I have an enum of for example \'Gender\' (Male =0 , Female =1) and I have another enum from a service which has its own Gender enum (Male =0

Answer 1

In case when the enum members have different values, you can apply something like this:

public static MyGender? MapToMyGender(this Gender gender)
{
    return gender switch
    {
        Gender.Male => MyGender.Male,
        Gender.Female => MyGender.Female,
        Gender.Unknown => null,
        _ => throw new InvalidEnumArgumentException($"Invalid gender: {gender}")
    };
}

Then you can call: var myGender = gender.MapToMyGender();

Update: This previous code works only with C# 8. For older versions of C#, you can use the switch statement instead of the switch expression:

public static MyGender? MapToMyGender(this Gender gender)
{
    switch (gender)
    {
        case Gender.Male: 
            return MyGender.Male;
        case Gender.Female:
            return MyGender.Female;
        case Gender.Unknown:
            return null;
        default:
            throw new InvalidEnumArgumentException($"Invalid gender: {gender}")
    };
}