[excel] Get length of array?

I'm trying to get the length of an array, yet I keep getting this error:

Object required

Am I doing something wrong?

Dim columns As Variant
columns = Array( _
"A", "ID", _
"D", "Name")
Debug.Print columns.Length  ' Error: Object required

Try CountA:

Dim myArray(1 to 10) as String
Dim arrayCount as String
arrayCount = Application.CountA(myArray)
Debug.Print arrayCount

Compilating answers here and there, here's a complete set of arr tools to get the work done:

Function getArraySize(arr As Variant)
' returns array size for a n dimention array
' usage result(k) = size of the k-th dimension

Dim ndims As Long
Dim arrsize() As Variant
ndims = getDimensions(arr)
ReDim arrsize(ndims - 1)
For i = 1 To ndims
    arrsize(i - 1) = getDimSize(arr, i)
Next i
getArraySize = arrsize
End Function

Function getDimSize(arr As Variant, dimension As Integer)
' returns size for the given dimension number
    getDimSize = UBound(arr, dimension) - LBound(arr, dimension) + 1
End Function

Function getDimensions(arr As Variant) As Long
' returns number of dimension in an array (ex. sheet range = 2 dimensions)
    On Error GoTo Err
    Dim i As Long
    Dim tmp As Long
    i = 0
    Do While True
        i = i + 1
        tmp = UBound(arr, i)
    Loop
Err:
    getDimensions = i - 1
End Function

If the variant is empty then an error will be thrown. The bullet-proof code is the following:

Public Function GetLength(a As Variant) As Integer
   If IsEmpty(a) Then
      GetLength = 0
   Else
      GetLength = UBound(a) - LBound(a) + 1
   End If
End Function

Function

Public Function ArrayLen(arr As Variant) As Integer
    ArrayLen = UBound(arr) - LBound(arr) + 1
End Function

Usage

Dim arr(1 To 3) As String  ' Array starting at 1 instead of 0: nightmare fuel
Debug.Print ArrayLen(arr)  ' Prints 3.  Everything's going to be ok.