Message-ID: <3ABA005C.4B1E1B74@earthlink.net>
From: Martin Ambuhl <mambuhl AT earthlink DOT net>
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Subject: Re: Strange behavior in loops!!
References: <99ctq8$t29$1 AT saphir DOT jouy DOT inra DOT fr>
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Date: Thu, 22 Mar 2001 13:35:28 GMT
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Eric Wajnberg wrote:
>
> Now look at the following other code:
> 
> #include <stdio.h>
> int main(void)
> {
>  float from=.3,to=.5,by=.05;
>  float x;
>  for (x=from;x<=to;x+=by)
>   (void)printf("%g\n",x);
>  return 0;
> }
> 
> Which is exactly the same than the previous one except that all values
> have been divided by 10.
> 
> In that case, the values outputted are .3, .35, .4, and .45.
> 
> In other words the value ".5" (i.e., the last one) is not outputted.
> 
> Strange, isn'it?

No.  5/100 = 1/20 is not a binary fraction.  It cannot be expressed exactly in
a binary mantissa.