Option Base with User-Defined Type Incorrect in Help Topic (135879)

SYMPTOMS

In the versions of Microsoft Excel listed above, the Help topic for the Visual Basic Option Base statement contains the following information:

The Option Base statement has no effect on arrays within user-defined types for which the lower bound is always 0.

This information is not entirely correct.

CAUSE

This statement is not true for an array within your user-defined type. For example, when you run the following code, the value 1 is returned, instead of the expected value 0 for the lower bound of the array within the user- defined type Mytype:

     Option Base 1

   Type Mytype
       Machine(2) As String
   End Type

   Sub Test_Mytype()
       Dim Test As Mytype
       MsgBox LBound(Test.Machine)
   End Sub

WORKAROUND

Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements. If you want the lower bound for an array within your user-defined type to be zero, you can use any of the following methods.

Method 1

Use the "To" clause to explicitly define the upper and lower bounds of your array. This method overrides any Option Base settings in your module. The following is an example of using this method:

   Type Mytype
      Machine(0 To 2) As String
   End Type

Method 2

Use the Option Base statement with the value 0 by adding the following statement at the beginning of your module:

   Option Base 0

Method 3

Do not use the Option Base statement at all; the default base is 0.