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Newsgroups: comp.lang.java.programmer
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