Subj : Re: Math error ??? doen't make sense!
To   : borland.public.cpp.borlandcpp
From : waking
Date : Fri Jul 02 2004 08:50 am

On Thu, 1 Jul 2004 21:53:22 -0400, "Stan DeGroff" <sdegroff@bright.net> wrote:

>int x,y;
>long int z;
>x=7000;
>y=12000;
>z=x*y;

Since both x and y are ints (16 bits), the temporary variable used for 
the result of the multiplication before the allocation to z occurs is also
an int. A 16-bit int is not large enough to hold the product, and hence
truncation occurs. This can be avoided by promoting at least one of 
the variables to a long via a typecast. e.g. - z=(long)x*y; or z=x*(long)y;
Then a long will be used for the temporary intermediate variable.

For 32-bit targets an int is already 32-bits, the same size as a long,
and therefore the cast is not needed.

--
Wayne A. King 
(waking@idirect.com, Wayne_A_King@compuserve.com)

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