Re: #20673 [Opn->Ver]: Inexplicable arithmetical error due to references

iliaa@php.net wrote in php.bugs: > [2002-11-27 07:04:52] dakota@dir.bg > > <? > $a = 7; > $a = $a + $a++; > echo $a; > //the result is 14; > ?> > > When I add a reference to $a, the behavior of $a + $a++ becomes > inexplicable different. Note that $a isn't changed anywhere! > > <? > $a = 7; > $b =& $a; > $a = $a + $a++; > echo $a; > //the result is 15; > ?> > > The only difference is $b =& $a, but why $a takes care of references to > itself? Ilia verified the bug, and I can reproduce that behaviour here as well. But I'm not sure whether the expressions $a = $a + $a++; or $x = $a + $a++; really are valid/legal/well-defined expressions. When exactly is that $a++ meant to be interpreted/executed? Before or after that other $a is looked at? I know that PHP is not C, but hasn't that something to do with sections 3.1 to 3.3 of the C FAQ, <http://www.eskimo.com/~scs/C-faq/s3.html>? Regards... Michael