Re: CompareWithoutRegardToCase

From: Buster (none_at_none.com)
Date: 09/27/04 

Date: Mon, 27 Sep 2004 16:51:10 +0100

JKop wrote:
> Comments, Questions and Suggestions please!
>
>
> Returns true if strings are identical, returns false if strings are not
> identical. (without regard to case).
>
>
> bool CompareWithoutRegardToCase(const char* x, const char* y)
> {
> //Undefined Behaviour if supplied with null pointers ;-D
>
> if ( !*x || !*y ) //valid pointer to null string
> {
> if ( !*x && !*y ) return true; //2 null strings are equal.
>
> return false;
> }
>
> do
> {
> if ( tolower( static_cast<unsigned char>(*x) ) == tolower(
> static_cast<unsigned char>(*y) ) ) continue;
> else
> {
> return false;
> }
> }
> while ( (++x,++y) ,*x );
>
> return !*y;
> }

What happens if the null-terminated string to which y points is longer
than the one pointed to by x?

bool CompareWithoutRegardToCase (char x, char y)
{
   return std::tolower (static_cast <int> (x))
       == std::tolower (static_cast <int> (y);
}

bool CompareWithoutRegardToCase (const char * x, const char * y)
{
   // Undefined behaviour if supplied with null pointers

   while ((* x) && (* y) && CompareWithoutRegardToCase (* x, * y))
   {
     ++ x;
     ++ y;
   }

   return ! ((* x) || (* y));
} 

--
Regards,
Buster

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