## A Penny for Your Thoughts

If you’re a Canadian developer writing POS software, you have probably implemented a Penny Rounding algorithm to deal with the removal of the Canadian Penny from circulation. An issue with writing such software is ensuring it works with a variety of regional settings, especially if the target machines are not locked down, or require support for multiple languages.

My implementation is as follows:

function PennyRound(Value :Currency) :Currency; { Implements the Canadian Penny Rounding algorithm to round to a 5 cent value. } var sTemp :string; LastDigit :Char; begin sTemp := FloatToStrF(Value,TFloatFormat.ffFixed,15,2); LastDigit := sTemp[Length(sTemp)]; if CharInSet(LastDigit,['2','7']) then begin //round down by subtracting 0.02 Result := Value - 0.02; end else if CharInSet(LastDigit,['1','6']) then begin //round down by subtracting 0.01 Result := Value - 0.01; end else if CharInSet(LastDigit,['4','9']) then begin //round up by adding 0.01 Result := Value + 0.01; end else if CharInSet(LastDigit,['3','8']) then begin //round up by adding 0.02 Result := Value + 0.02; end else //value is already in 5 cent increments if CharInSet(LastDigit,['5','0']) then begin Result := Value; end; end;

Anyone have a better implementation?