Big hex numbers negative?

[Shachar Shemesh]

Fabian Cenedese wrote:

>Hi
>
>While testing more variant functions I tried this on Windows:
>
>double dVal;
>OLECHAR test1[]={'&', 'H', '8', '0', '0', '0', '0', '0', '0', '0', '\0'};
>ok=VarR8FromStr(test1, LANG_NEUTRAL, NUMPRS_STD, &dVal);
>
>The result for dVal was -2147483648. But as a real value it shouldn't
>have any problems holding the "real" value 2147483648. So why has
>it become negative? Is it because the source form was a hex number?
>Are all hex numbers automatically signed if converted to int/real? Or
>just because of the 32nd bit? The documentation wasn't that informative.
>
>(The funny thing though was this remark in my VC6 help, it's not
>in the online version of MSDN anymore:
>Passing into this function any invalid and, under some circumstances, NULL pointers will result in unexpected termination of the application. For more information about handling exceptions, see Programming Considerations.
>
>...now I understand many things :)
>
>Thanks
>
>bye   Fabi
>
>
>
>  
>
I'm not sure I understood your question properly.
A signed 2 complement 32 bit var can hold the numbers (-2^31) to 
(2^31)-1. That's just how the encoding works. Was that your question?

             Shachar

-- 
Shachar Shemesh
Lingnu Open Systems Consulting
http://www.lingnu.com/