Re: Expression statements

[Jonathan Castello <twisolar@...>]

On Mon, Aug 16, 2010 at 11:50 AM, Shaun McVey <shaun.mcvey@gmail.com> wrote:
>>
>> In my opinion, the C/C++ behavior is just a side effect of C-strings
>> being terminated by a null byte, aka 0. Since C didn't have a true
>> boolean type (correct me if I'm wrong), 0 was used as a false value.
>> Hence, an empty string is treated as a false value.
>>
>
> I don't think that's the case, whether a string in C is empty (null
> terminated) or not doesn't affect the truth value of it.
>
> --
> char *s = "hello";
> char *t = "";
>
> if (s)
>  printf("s is true\n");
>
> if (t)
>  printf("t is true\n");
>
> Both will print a message saying they're true, because s and t are
> pointers to locations in memory which are both true.  C more likely
> deals with truth values as a consequence of how underlying hardware
> typically treats 0 as false and everything else as true.  C strings
> would've been built on top of that behaviour.
>

D'oh, you're right. It would only be false if you did if (*t) {}. I'm
a bit out of practice with my C(++), as you can see!

In which case, I'm confused. Which language actually makes "" a false value?

~Jonathan