How Excel VBA rounds Doubles to Integers?

Question

I am trying to understand the type of errors that could happen when a wrong type of variable is declared in VBA.

This is the code I am using:

Sub t         


        

Answer 1

Sandra, it will round up or down depending if it is an even or odd number. If it is an even number, it will be round down. Otherwise, it will round up.

Answer 2

In order to avoid so called banker's rounding (= midpoint value 5 always rounds to the nearest even number ) you can use

• (1) WorkSheetFunction.Round
• (2) a user defined function.

Banker's rounding is a standard form of rounding used in financial and statistical operations in order to minimize significant rounding errors over multiple rounding operations by consistently rounding midpoint values in a single direction.

(1) Example using the WorksheetFunction Round()

Sub RoundWithWorkSheetFunction()
' Purpose: avoid so called bankers' rounding in VBA (5 always rounds even)
With WorksheetFunction
    Debug.Print "WorksheetFunction.Round(3.5, 0)=" & .Round(3.5, 0), ":| VBA rounds to " & Round(3.5, 0)
    Debug.Print "WorksheetFunction.Round(4.5, 0)=" & .Round(4.5, 0), ":| VBA rounds to " & Round(4.5, 0)
End With

End Sub

(2) An alternative to the worksheet function (avoiding bankers' rounding):

Function roundIt(ByVal d As Double, ByVal nDigits As Integer) As Double
' Purpose: avoid so called bankers' rounding in VBA (5 always rounds even)
If nDigits > 0 Then
   ' if continental european colon instead of point separartor
   ' roundIt= val(Replace(Format(d, "0." & String(nDigits, "0")), ",", "."))
     roundIt = Val(Format(d, "0." & String(nDigits, "0")))
Else
   ' if continental european colon instead of point separartor
   ' roundIt =  val(Replace(Format(d / (10 ^ nDigits), "0."), ",", "."))
   roundIt = Val(Format(d / (10 ^ nDigits), "0."))
End If
End Function