From: Tim Hunter <TimHunter@...>
Date: 2009-06-19T06:15:12+09:00
Subject: Re: floating point accuracy in JRuby

Steven D. Arnold wrote:
> [ 03:23 PM (5) omega:thoth ~ ] > jirb
> irb(main):001:0> 0.1+0.1+0.1+0.1+0.1+0.1+0.1+0.1+0.1+0.1
> => 0.9999999999999999
> [ 03:33 PM (8) omega:thoth ~ ] > irb
>  >> 0.1+0.1+0.1+0.1+0.1+0.1+0.1+0.1+0.1+0.1
> => 1.0
> 
> Disappointing that JRuby does not handle floating point numbers (a) in 
> the the same way as CRuby and (b) not as accurately.  Is the cost of 
> implementing CRuby's behavior prohibitively high on the JVM, is there a 
> fix planned in the future?  How would JRuby users recommend handling 
> currency on that platform?
> 
> steven
> 
> 

I don't think it's a good idea to use binary floating-point numbers for 
currency in any language or any platform. See the numerous previous 
discussions of binary vs. decimal arithmetic on this list.

Use integer cents instead, or BigDecimal.

-- 
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