Determining the Number of Dimensions in an Array Variable

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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. The easiest way to determine the number of dimensions in a Visual Basic for Applications array variable is to get the routine to attempt a task with each dimension. When it attempts to do the task to a nonexistent dimension, an error will be returned. An error handler can be used to return the dimension in which the task was last successful. One way to test a dimension is by using the LBound function. The LBound function takes two arguments, the array variable and the specific dimension, and returns the lower bounds of that dimension. Using this function on a nonexistent dimension returns an error. Coupled with an error handler, this can be used to determine the number of dimensions.

Sample Visual Basic Procedure

This routine tests the array named Xarray by testing the LBound of each dimension. Using a For...Next loop, the routine cycles through the number of possible array dimensions, up to 60000, until an error is generated. Then the error handler takes the counter step that the loop failed on, subtracts one (because the previous one was the last one without an error), and displays the result in a message box.

   Sub NumberOfDimensions()

      'Dimensions Xarray as an array.
      Dim Xarray(1 to 10, 5 to 20, 256 to 300, 8, -5 to 0)

      'Sets up the error handler.
      On Error GoTo FinalDimension

      'Visual Basic for Applications arrays can have up to 60000
      'dimensions; this allows for that.
      For DimNum = 1 to 60000

         'It is necessary to do something with the LBound to force it
         'to generate an error.
         ErrorCheck = LBound(Xarray, DimNum)

      Next DimNum

      Exit Sub

      ' The error routine.
   FinalDimension:

      MsgBox "The array has " & DimNum - 1 & " dimensions"

   End Sub