Bill
Thanks, I thought the cast would have told the compiler to reserve a storage space for a double. I suppose because I added the .0 to each of the values it know that they were floats/doubles?
However if I use the following it also gives an incorrect result.
Unsigned long long test = 0;
Test = (2482884 * 1024);
Printf("%llu\n",test);
I get 18446744071957057536 that is not wrapping but it certainly gives me the wrong answer?? Why would that happen?
Chris...
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-----Original Message-----
From: c400-l-bounces+chrish=shieldadvanced.ca@xxxxxxxxxxxx [mailto:c400-l-bounces+chrish=shieldadvanced.ca@xxxxxxxxxxxx] On Behalf Of Bill Seurer
Sent: June-01-11 12:24 PM
To: C programming iSeries / AS400
Subject: Re: [C400-L] Conversion to double.
c400-l-bounces+seurer=us.ibm.com@xxxxxxxxxxxx wrote on 06/01/2011
c400-l-bounces+11:17:23
AM:
Printf(“%f\n”,(double)(2482884 * 1024)); shows -1752494080.000000
Printf(“%f\n”,(2482884.0 * 1024.0)); shows 2542473216.000000
Printf(“%f\n”,((double)2482884 * (double)1024)); shows
2542473216.000000
It seems like the conversion to double does not work in the first
instance.
Am I doing something wrong? Shouldn’t the cast of the result make the
number correct?
2482884 * 1024 is 2,542,473,216 or in hex 0x978B1000. That is larger than the largest positive value that can fit in a signed integer (0x7FFFFFFF) so the value "wraps" and becomes negative.
-Bill
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