Valdhor already gave you all the info you need, but I like the sound of my own fingers typing. I also like to procrastinate, so I'm in heaven right now :p
- Some numbers that are easy to represent in decimal are hard to represent in binary, just as some numbers that are easy to represent in base 60 are hard to represent in decimal (such as 1/3). - Your calculations are safe enough: Number has a very high precision and calculations are carried out with full precision. It's just when testing for equality that you can run into problems -- I'm guessing this is where you noticed the discrepancy? - When comparing for floating-point numbers for equality, you need to specify a tolerance too. Most unit-testing frameworks provide this for their floating-point asserts. And when I was doing financial apps, we did the same thing. If you *really* need higher precision, you'll need a BigNumber implementation for AS3, of which there are several. The AS3Crypto library has one I believe... Chyaaaars :) Jules On Thu, Dec 18, 2008 at 03:15, Ken Johnson <[email protected]> wrote: > 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 > > > -- Cheers, Jules -- Jules Suggate Owner and Technical Lead Uphill Sprint Limited +64-21-157-8562
