Re: test if a string is a valid 'number'?

From:

"Tom Serface" <tom.nospam@camaswood.com>

Newsgroups:

microsoft.public.vc.mfc

Date:

Wed, 30 May 2007 23:51:29 -0700

Message-ID:

<29407DFC-8C96-4A51-AF7B-A8B0F59C8379@microsoft.com>

<Best Dr. McCoy Voice>It's a joke Jim</Best Dr. McCoy Voice>

Tom

"Joseph M. Newcomer" <newcomer@flounder.com> wrote in message
news:rnds531a69n0je9isnctotpq85rqoka6mm@4ax.com...

See below...
On Wed, 30 May 2007 13:28:16 -0700, "Ashot Geodakov"
<a_geodakov@nospam.hotmail.com>
wrote:

#include <windows.h>

typedef long ( *ISNUMERIC )( VARIANT* );

BOOL IsNumeric( LPTSTR szString )
{
   HINSTANCE hinstLib;
   ISNUMERIC ProcAdd;

   hinstLib = LoadLibrary( TEXT( "C:\\Program Files\\Common
Files\\Microsoft Shared\\VBA\\VBA6\\vbe6.dll" ) );

   if( hinstLib != NULL )
   {
       long lNumeric = 0;
       ProcAdd = (ISNUMERIC)GetProcAddress( hinstLib, "rtcIsNumeric" );

       if( NULL != ProcAdd )
       {
           VARIANT vtExpression;
           vtExpression.vt = VT_BSTR;
           vtExpression.bstrVal = SysAllocString( szString );
           __asm
           {
               lea eax, [vtExpression]
               push eax
               call (ProcAdd)
               mov lNumeric, eax
           }

****
This is a weird way to write
INumeric = ProcAdd(&vtExpression);
Why revert to assembly code to do something that is already available in C
without any
effort at all?
****

           SysFreeString( vtExpression.bstrVal );
       }

       FreeLibrary( hinstLib );

*****
Given the complexity and horrendous inefficiency of this solution, why is
it even a
candidate for consideration compared to writing a rather straightforward
FSM in C?
*****

       return ( lNumeric != 0 );
   }
   else return FALSE;
}

void main( void )
{
   BOOL bNumeric = IsNumeric( TEXT( "1245789.00" ) );
   bNumeric = IsNumeric( TEXT( "sdf1245789.00" ) );
   bNumeric = IsNumeric( TEXT( "+234.43E-24" ) );
   bNumeric = IsNumeric( TEXT( "12,234,345.00" ) );
   bNumeric = IsNumeric( TEXT( "sdf1245789.00" ) );
}

"WJ" <WJ@discussions.microsoft.com> wrote in message
news:B191F239-907C-4468-B8D6-B794460DF3C5@microsoft.com...

Hi,
I have a string that I want convert to a number. Before doing that, I
need
to test if the string represents a valid 'number'.

I remember there is a function to do that, but I can't find it.
(I am NOT using .net, I am using MFC)

Thanks.

Joseph M. Newcomer [MVP]
email: newcomer@flounder.com
Web: http://www.flounder.com
MVP Tips: http://www.flounder.com/mvp_tips.htm