ActionScript's Number follows the IEEE 754 floating point standard ( http://en.wikipedia.org/wiki/IEEE_754 ). It's essentially lossy by design.
It's not the really the right thing to use for financial calculations, but ActionScript doesn't really have alternatives. It has essentially two numeric types int (with--obviously--only integer precision) and the above-mentioned Number. One approach would be to do all your math in cents (or tenths of cents) using ints and convert for display to the user. Another would be to write your own numeric class that works to the precision you need. There may be some out there already, since it seems like this would come up pretty often (a quick search seems to confirm this). -- Maciek Sakrejda Truviso, Inc. http://www.truviso.com -----Original Message----- From: Ken Johnson <kenjohnso...@hotmail.com> Reply-To: flexcoders@yahoogroups.com To: flexcoders@yahoogroups.com Subject: [flexcoders] Rounding error Date: Wed, 17 Dec 2008 14:15:54 -0000 Hi Everyone - Given the following code: var num1:Number = 0.72; var num2:Number = 0.198; var num3:Number; num3 = num1; num3 += num2; I would expect num3 to equal 0.918. Instead, it equals 0.9179999999999999. And when I apply a number formatter with a precision of 2, I get 0.91. I am performing financial calculations, and this is not acceptable. Am I doing something wrong here? Thanks for your help! Ken
