VB.NET Enumeration Representation

Question

Is it guaranteed that the numeric values for an Enum with only uninitialized values start at zero and increment by one in the order defined?

Answer 1

Yes. If you set one explicitly, the ones after it also increment.

That allows you to have:

class Program
{
    static void Main(string[] args)
    {
        Console.WriteLine((int)Seasons.Spring);
        Console.WriteLine((int)Seasons.Summer);
        Console.WriteLine((int)Seasons.Autumn);
        Console.WriteLine((int)Seasons.Fall);
        Console.WriteLine((int)Seasons.Winter);
        Console.Read();
    }
}

public enum Seasons
{
    Spring,
    Summer,
    Autumn,
    Fall = Autumn,
    Winter
}

Output: 0 1 2 2 3

And they will have values 0, 1, 2, 3 and Fall will have the same value as Autumn.

Sorry, my example is in C# but the same applies for VB.net

Answer 2

Yes. From the documentation:

If you do not specify initializer for a member, Visual Basic initializes it either to zero (if it is the first member in member list), or to a value greater by one than that of the immediately preceding member.

http://msdn.microsoft.com/en-us/library/8h84wky1(VS.80).aspx