An enumerated type is simply a list of constants, each of which has a unique value. An Enum can improve the readability of your code by allowing you to declare a variable of your enumerated type, then assign one of the elements of the Enum to the value of the variable. Visual Basic makes this easy by providing you with a list of values for your variable as you use it:
Public Enum TimeOfDay Morning = 0 Afternoon = 1 Evening = 2End EnumSub Main() Dim RightNow As TimeOfDay If Time >= #12:00:00 AM# And Time < #12:00:00 PM# Then RightNow = Morning ElseIf Time >= #12:00:00 PM# And Time < #6:00:00 PM# Then RightNow = Afternoon ElseIf Time >= #6:00:00 PM# Then RightNow = Evening End IfEnd Sub
Validity checking is not done when assigning values to the special-typed variable. Even though the TimeOfDay values range from zero to two, VB doesn’t attempt to keep you from assigning a value of four, or another number, to such a variable. Be especially aware of this when writing Property Let procedures, which accept an enumerated parameter.