Date: Wed, 15 Oct 1997 18:03:02 -0700 (PDT)
Message-Id: <199710160103.SAA04693@adit.ap.net>
Mime-Version: 1.0
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To: br5an AT aol DOT com (Br5an), djgpp AT delorie DOT com
From: Nate Eldredge <eldredge AT ap DOT net>
Subject: Re: ' ^ '
Precedence: bulk

At 04:36  10/15/1997 GMT, Br5an wrote:
>Mike wrote:
>
>>Hi. I'm just a casual programmer, so excuse me if this is a foolish
>>question. I cannot get the ^ operator to work in my programs using DJGPP. It
>>returns error messages basically saying it doesn't know what it is. I'll try
>>something like this:
>
>>    cout << 3^2;
>
>>and it happens. Do I have to include some weird header file, or am I just
>>screwed? Any help appreciated.
>
>  Mike,
>            In "C"   ^  is the binary operator XOR.  As it appears on the
> surface I would think your code should work.  But obviously it isn't working
> for you.  I might suggest that you try  cout << (3^2); and see if that helps. 
> On the chance that you wanted 3 raised to the 2nd power, you'd want to look at
> the function call    pow(3, 2);
>#include <math.h> pow(...)   really expects two doubles to be passed to it and
> returns a double, but I think this should work.  Sorry for posting without
> testing anything.  Perhaps someone will be along and clarify the situation.
Yes, you are right about all that. pow() does indeed do exponentiation. But
it does take floating-point numbers (double) for args and return. If you
want to work on integers you may have loss of precision when using this
floating-point function. For integers you can do something like:
int int_pow(int x, int y)
{
   int i;
   int t = x;
   for (i=1; i < y; i++) t *= x;
   return t;
}

HTH

Nate Eldredge
eldredge AT ap DOT net