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NNTP-Posting-Date: Sun, 11 Sep 2011 21:25:10 -0500
Message-ID: <4E6D6D89.6AEF@mindspring.com>
Date: Sun, 11 Sep 2011 22:25:13 -0400
From: pete <pfiland@mindspring.com>
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Subject: Re: Unexpected output
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Xref: x330-a1.tempe.blueboxinc.net comp.lang.c:10149

Ben Bacarisse wrote:
> 
> August Karlstrom <fusionfile@gmail.com> writes:
> 
> > On 2011-09-10 21:36, Mazen wrote:
> >> Hello,
> >>
> >> Following is a simple program:
> >>
> >> #include<stdio.h>
> >>
> >> int main(void) {
> >>    int i = 0, j, k;
> >>    j = k = 2;
> >>
> >>    printf("%d %d\n", i=+j, i=-j);
> >>
> >>    return 0;
> >> }
> >>
> >> The output is
> >> 2 2
> >>
> >> Shouldn't the second expression be -2 rather than 2? I'm confused.
> >> Your insights pls. Thanks!
> >
> > One obvious insight is that it's best to avoid side effects in
> > expressions if possible.
> 
> The devil is in the detail.  You presumably think that x = 1; is OK so
> what about x++? 

(x = 1) has a side effect in an expression.
I avoid side effects in arguments in function calls.

-- 
pete