Re: String: can someone explain this...

[Harald van Pee]

Albert Schueller wrote:
> 
> Hi,
> 
> Why do the two couts in this snippet of code printout different things when
> response = "no"; but the same thing when response = "yes";?
> 

The result of find_first_of() is of type size_type (size_t).
in general int is no size_type, because you need no negative value
for size types
-> if find_first_of() finds a position, 1 or 2 fits into int.
if not, the result is result.npos (in general a very big number, illegal
character position)
maybe 2^32-1 -> doesn't fit into int
-> use
size_t position;

and there will be no problem!

Regards
Harald


> ///////////////////////////////////////////////////////////////////////////
> 
> #include <iostream>
> #include <string>
> 
> int main() {
>   string response("no");
>   int position;
> 
>   cout << response.find_first_of("yY") << endl;
>   position  = response.find_first_of("yY");
>   cout << position << endl;
> 
>   return 0;
> }
> 
> --
> Albert Schueller                                 Department of Mathematics
> Office Phone:  509-527-5140                      Whitman College
> Public Key:  http://carrot.whitman.edu/gpg.key   Walla Walla, WA USA 99362