» Return error values from user defined functions using VBA in Microsoft Excel

Return error values from user defined functions
With the example function below you can get user defined functions to return error values
just like the built in functions in Excel do.

Function DummyFunctionWithErrorCheck(InputValue As Variant) As Variant
    If InputValue < 0 Then ' return an error value
        DummyFunctionWithErrorCheck = CVErr(xlErrNA) ' retunerer #I/T!
        ' xlErrDiv0, xlErrNA, xlErrName, xlErrNull, xlErrNum , xlErrRef, xlErrValue
        Exit Function
    End If
    ' do the calculation
    DummyFunctionWithErrorCheck = InputValue * 2
End Function