Question

Say you have a function that returns an enum:

public enum ServerStatus
{
    Down,
    Up
}

private ServerStatus GetServerStatus(int time)
{
    if (time >= 0 && time < 12)
    {
        return ServerStatus.Down;
    }
    else if (time >= 12 && time <= 23)
    {
        return ServerStatus.Up;
    }
    else
    {
        return ?? // Server status is neither Up nor Down
    } 
}

Should I:

1. Add “Neither” to ServerStatus
2. Makes GetServerStatus return ServerStatus? and return null
3. Return a another bool that indicate if the value is meaningful

Answer 1

If that case should never happen in practice, and you don’t expect to have to produce something other than ‘Up’ and ‘Down’, then you should throw an exception.