Ternary Datatype : True, False, Null 
Author Message
 Ternary Datatype : True, False, Null

Is there a .NET datatype to use which is essentially a boolean but can also
take a 3rd state of being neither (Null - or 'mu')?

Sometimes I find myself wanting to do this.  Especially with procedure
return values.

Phil (New Zealand - Aotearoa)

Wed, 29 Dec 2004 10:34:08 GMT  
 Ternary Datatype : True, False, Null

>Is there a .NET datatype to use which is essentially a boolean but can also
>take a 3rd state of being neither (Null - or 'mu')?

You could certain create such a thing, see below.  However my experience has
been that it's better to change the design such that tristate values are not

Namespace Test
   Enum TristateValue
   End Enum 'TristateValue

   Class Class1

      'Entry point which delegates to C-style main Private Function
      Public Overloads Shared Sub Main()
      End Sub

      Overloads Shared Sub Main(args() As String)
         Select Case foo()
            Case TristateValue.Yes
            Case TristateValue.No
            Case TristateValue.Undecided
         End Select
      End Sub 'Main

      Shared Function foo() As TristateValue
         Return TristateValue.Yes
      End Function 'foo
   End Class 'Class1
End Namespace 'Test


*--------={ Fine Art for .NET }=--------*


       Turn on, tune in, download.

Wed, 29 Dec 2004 10:39:01 GMT  
 [ 2 post ] 

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