Validate Float Logic?

This is a discussion on Validate Float Logic? within the Windows Programming forums, part of the Platform Specific Boards category; I spent the evening trying to figure a good way to validate user input of a floating point number from ...

  1. #1
    Registered User Bajanine's Avatar
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    Question Validate Float Logic?

    I spent the evening trying to figure a good way to validate user input of a floating point number from a string . The following code snippet works, but seems complicated to me. I am sure there is probably a more efficient way. If so could someone please give me some constructive criticism or pointers.


    Code:
    ////////////////////////////////////
    // Validate floating point number.//
    ////////////////////////////////////
    
    int Decimal = 0;
    
    for (int i = 0; i < nLen; i++ )
    {
    if ( !isdigit(pbuffer[i]))
    {
    		if ( Decimal == 0 )
    		{
    			if( pbuffer[i] == '.' )
    			{
    				Decimal = 1;
    				continue;
    			}
    		}
    		MessageBox (NULL, TEXT ("Enter a floating point number."), 
    			TEXT ("Invalid input!"), MB_ICONINFORMATION) ;
    		return TRUE;	// break out of switch statement.
    }
    }
    
    // pbuffer is valid so do calculations.
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  2. #2
    ¡Amo fútbol!
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    http://www.dinkumware.com/manuals/re...ib.html#strtod

    This might help.

    EDIT: The link only works sometimes. Once you get in there, look up strtod if it doesn't automatically bring you to it.

  3. #3
    Registered User Bajanine's Avatar
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    Thumbs up Thanks for the info.

    Thanks for the info. I'll try it out.
    Favorite Quote:

    >For that reason someone invented C++.
    BLASPHEMY! Begone from my C board, you foul lover of objects, before the gods of C cast you into the void as punishment for your weakness! There is no penance for saying such things in my presence. You are henceforth excommunicated. Never return to this house, filthy heretic!



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