How to find the number of dimensions that an array has?

Question

Below is a piece of code where I need to store some info about a warning message by going through messages passed. The parameter passed itself is a variant which is set by a

Answer 1

An array has 2 bounds: Upper and Lower.

I think you're asking where the lower bound begins.

By default, the lower bound is zero. For example:

Sub test()
    Dim arr
    arr = Array("a", "b", "c")
    Debug.Print "Lower: " & LBound(arr), "Upper: " & UBound(arr)
End Sub

returns: Lower: 0 Upper: 2 because the 3 elements have indices of 0, 1, and 2.

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Some functionality may begin at 1 by default but it's rare. One example is filling an array with a range:

Sub test()
    Dim arr
    arr = Range("A2:A4")
    Debug.Print "Lower: " & LBound(arr), "Upper: " & UBound(arr)
End Sub

...returns: Lower: 1 Upper: 3

---

If you fully declare the array, you can make the upper and lower bound whatever you want:

Sub test()
    Dim arr(99 To 101) As String
    arr(100) = "blah"
    Debug.Print "Lower: " & LBound(arr), "Upper: " & UBound(arr)
End Sub

...returns: Lower: 99 Upper: 101, but an array with declared bounds won't work with many functions (like the previous examples.

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You can also set the default lower bound with an statement at the very top of each module:

Option Base 1

...but there are so many places it doens't apply it's kind of useless. (More here.)

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See also:

• MSDN : Declaring Arrays (Fixed & Dynamic)

• MSDN : LBound Function

• MSDN : UBound Function

Answer 2

Is it possible to find the number of dimensions of an array in VBA?

This approach increments the possible dimensions count, 60 being the built in maximum (c.f. comment):

Private Function nDim(ByVal vArray As Variant) As Long
' Purpose: get array dimension (MS)
Dim dimnum     As Long
Dim ErrorCheck As Long    ' OP: As Variant
On Error GoTo FinalDimension

For dimnum = 1 To 60        ' 60 being the absolute dimensions limitation 
    ErrorCheck = LBound(vArray, dimnum)
Next
' It's good use to formally exit a procedure before error handling
' (though theoretically this wouldn't needed in this special case - see comment) 
Exit Function

FinalDimension:
nDim = dimnum - 1

End Function

Further links (thx @ChrisNeilson)

MS Using arrays

Big Array