Welcome to the wild and wooly world of floating point arithmetic. If you know that there are always going to be a fixed number of decimal places, you're often better off storing the value as an integer and adding scaling logic where needed. This is because the values that can be stored accurately as floating point numbers are only those whose mantissa can accurately be expressed as a sum of powers of two. These values include 0.25 (which equals 2^-2) but does not include 0.26.
In general, rounding a decimal to an integer is equivalent to adding 0.5 and then truncating. In your case, this would mean uint nIntAmount = (uint)((objMyObject.Amount * 100) + 0.5); In practice, if your domain really does include only values with "two decimal places" then it's sufficient to add only a token amount before truncating. However, the code is more readable and no slower by doing the complete rounding operation. On Mon, Aug 25, 2008 at 9:27 AM, Eddie Lascu <[EMAIL PROTECTED]> wrote: > Hello everyone, > > I have some objects that contain an amount field that is declared as > double. > Since it contains amounts, it always has only two decimal digits that are > significant. During the process I need to convert that double into an > integer by removing the decimal point. For example, $78.59 should be > converted to integer 7859 and $101.53 to 10153. in my code I have > uint nIntAmount = (uint)(objMyObject.Amount * 100); > > The problem I am facing is that sometimes, very rarely, there is a rounding > error that is introduced and the integer obtained is off by a cent (plus or > minus). For example, this is a line that was traced in my log file: > > "Updating the batch with $137.89 as the amount in the transaction. This > amount was converted to 13788." > > Can either of you suggest a different way to convert the amounts in > integers > without this nagging rounding error? > > Any help will be appreciated, > > Eddie > > =================================== > This list is hosted by DevelopMentor(R) http://www.develop.com > > View archives and manage your subscription(s) at > http://discuss.develop.com > =================================== This list is hosted by DevelopMentor® http://www.develop.com View archives and manage your subscription(s) at http://discuss.develop.com
