Re: PHP7 / foreach / references / ugly code / discrepancy to PHP 5.6

Should this be in the UPGRADING notes? > On 10.11.2015, at 20:45, Nikita Popov <nikita.ppv@gmail.com> wrote: > > On Tue, Nov 10, 2015 at 5:48 PM, Philip Hofstetter < > phofstetter@sensational.ch> wrote: > >> Hi, >> >> I'm having a cause of slightly ugly code that runs differently from PHP 5.6 >> to PHP 7 and I don't think this difference is documented, nor expected. As >> I'm not sure whether this is an intended change or not, I'm asking here >> firstr before making a bug report. >> >> The code in question is >> >> ---- >> $b = [1, 2, 3]; >> >> foreach($b ?: [] as &$v){ >> $v = $v*2; >> unset($v); >> } >> >> var_dump($b); >> ---- >> in PHP7, this produces >> >> array(3) { >> [0] => >> int(1) >> [1] => >> int(2) >> [2] => >> int(3) >> } >> >> whereas in PHP 5.6 and earlier, this produces >> >> array(3) { >> [0] => >> int(2) >> [1] => >> int(4) >> [2] => >> int(6) >> } >> >> what scares me about this is that in order to get the old behaviour in PHP7 >> back, you just have to get rid of the ?: operator: >> >> foreach($b as &$v){ >> >> is fine >> >> foreach($b ?: [] as &$v){ >> >> is not. >> >> I guess this is related to >> >> >> http://php.net/manual/en/migration70.incompatible.php#migration70.incompatible.foreach.by-value >> or >> >> >> http://php.net/manual/en/migration70.incompatible.php#migration70.incompatible.foreach.by-ref >> , >> but I'm not entirely sure whether this is actually intended behaviour - >> it's certainly unexpected to me that applying ?: now always makes a copy >> whereas before it didn't. >> > > This is a bug in PHP 5, which has been fixed in PHP 7 as a side-effect of > other changes. The new behavior is correct. This issue is tracked at > https://bugs.php.net/bug.php?id=70857. > > Nikita