Re: Bug #12566 Updated: Cascaded ternaries evaluate incorrectly

Fair enough :-) In which case there is a documentation bug, and the paragraph: another conditional operator is the "?:" (or ternary) operator, which operates as in C and many other languages. might perhaps read better: another conditional operator is the "?:" (or ternary) operator, which operates unlike C and all other languages. ;-) I appreciate the note on the historical accident, and in which case clearly the behaviour should indeed not be changed now. Cheers, Nick On Sat, Aug 04, 2001 at 09:21:33PM -0000, Bug Database wrote: > ID: 12566 > Updated by: jeroen > Reported By: nick@macaw.demon.co.uk > Status: Open > Bug Type: *Programming Data Structures > Operating System: Linux > PHP Version: 4.0.6 > New Comment: > > adam@trachtenberg.com: > > It's not a "bug," but a "feature." :) > > > > PHP has the inverse associativity of ?: compared to C (and every other > > language). This was originally a mistake, but now "it won't be changed," > > due to historical reasons. > > > > See some messages I had on php-dev back around the first week of January, > > 2001 on this topic. FWIW, I would like to change it. > > > > -adam > > So, you need to read it as: > > echo (TRUE ? 'one' : TRUE) ? 'two' : 'unknown';, > and > echo 'one' ? 'two' : 'unknown' is, correctly, 'two' > > > Maybe a fix for PHP 4.1 / PHP 5? > > > > Previous Comments: > ------------------------------------------------------------------------ > > [2001-08-04 17:04:43] jeroen@php.net > > Confirmed in latest CVS: > > --- > echo TRUE ? 'one' : TRUE ? 'two' : 'unknown'; > => two > --- > echo TRUE ? 'one' : FALSE ? 'two' : 'unknown'; > => two > --- > This definitely is a bug, and IMO a serious one. A parse error would be acceptable IMO (then > use ( and )), but this isn't. > > ------------------------------------------------------------------------ > > [2001-08-04 15:33:28] nick@macaw.demon.co.uk > > The following emits 'two' rather than 'one' as one would expect. > > $a = 1; $b = 2; > > echo (($a == 1) ? 'one' : > ($b == 2) ? 'two' : > 'unknown'); > > Apologies if for PHP this unusual behaviour actually is as expected, but being > counter-intuituve, and of course inconsistent from other languages with a ?: operator, this is an > undesirable result. > > In 'C', the following of course outputs 'one' > > #include <stdio.h> > > int main() > { > int a = 1, b = 2; > > puts((a == 1) ? "one" : > (b == 2) ? "two" : > "unknown"); > > return 0; > } > > > ------------------------------------------------------------------------ > > > > ATTENTION! Do NOT reply to this email! > To reply, use the web interface found at > http://bugs.php.net/?id=12566&edit=2