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Safely checking the bounds of an array

Safely checking the bounds of an array

Using the Ubound and Lbound functions on an uninitialised typed array causes a "Subscript out of range" error. Use the following simple functions to safely check the bounds of any variant datatype.

'Purpose     :  Replacement function to UBound. Returns Upper bound of an array.
'Inputs      :  avValues                The array to determine the upper bound of
'               lDimension              The dimension of the array
'               [lDefault]              The value to return if an error occurs
'Outputs     :  The upper bound specific dimension of avValues
'Notes       :  This function uses UBound with an error handler and allows you to specify a default return value


Function UUBound(avValues As Variant, Optional lDimension As Long = 1, Optional lDefault As Long = 0) As Long
    
    On Error GoTo ErrFailed
    UUBound = UBound(avValues, lDimension)
    Exit Function
    
ErrFailed:
    'Error Occurred, Return the Default and clear error
    UUBound = lDefault
    On Error GoTo 0
End Function


'Purpose   :    Replacement function for LBound (has extra functionality and error handling)
'Inputs    :    avValues            The array to find the LBound.
'               lDimension          Which dimension's lower bound to return
'               [lDefault]          The value to return if an error occurs
'Outputs   :    The lower bound of the array, or lDefault if an error occurs
'Notes     :    LBound raises and error if you try and check the the lower bound
'               of a dimension that doesn't exist.
Function LLBound(avValues, Optional lDimension As Long = 1, Optional lDefault As Long = 0) As Long
    On Error GoTo ErrFailed
    LLBound = LBound(avValues, lDimension)
    Exit Function
ErrFailed:
    LLBound = lDefault
End Function
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