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Re: double == double

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Subject	Re: double == double
Date	Wed, 12 Oct 2016 18:14:02 +0100
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On 12/10/2016 13:15, Stefan Ram wrote:
>   Sometimes it is taught that it makes no sense to compare
>   two double values with »==«.

This is not necessarily true. It is a good rule to stick to, given that 
most of the times double values are results of computations, therefore 
subject to round-off errors, but it is not always true that == would 
fail. Consider this:

         System.out.println(1.0 == 1.0);
         double x = 0;
         for (int i=0; i<50; i++) {
             x += 1.0/50.0;
         }
         System.out.println(x == 1.0);

On my machine, the first printing true, the second printing false.

If it is granted that the double values are internally represented the 
same way (see the literals above), they are equal.

-- 
4ndre4

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Re: double == double 4ndre4 <626401fd-4bc7-4f8f-b641-563ae0f72920@626401fd-4bc7-4f8f-b641-563ae0f72920.invalid> - 2016-10-12 18:14 +0100
  Re: double == double Arne Vajhøj <arne@vajhoej.dk> - 2016-10-14 22:37 -0400
    Re: double == double 4ndre4 <626401fd-4bc7-4f8f-b641-563ae0f72920@626401fd-4bc7-4f8f-b641-563ae0f72920.invalid> - 2016-10-15 07:36 +0100

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