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Date: Tue, 10 Nov 2015 11:08:55 -0800
Cc: PHP internals <internals@lists.php.net>
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To: Philip Hofstetter <phofstetter@sensational.ch>
Subject: Re: [PHP-DEV] PHP7 / foreach / references / ugly code / discrepancy to PHP 5.6
From: php_m@rtin.so (Martin Amps)

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Here=E2=80=99s a 3v4l demonstrating this too:

https://3v4l.org/OXAd3 <https://3v4l.org/OXAd3>


> On Nov 10, 2015, at 8:48 AM, Philip Hofstetter =
<phofstetter@sensational.ch> wrote:
>=20
> Hi,
>=20
> 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.
>=20
> The code in question is
>=20
> ----
> $b =3D [1, 2, 3];
>=20
> foreach($b ?: [] as &$v){
>    $v =3D $v*2;
>    unset($v);
> }
>=20
> var_dump($b);
> ----
> in PHP7, this produces
>=20
> array(3) {
>  [0] =3D>
>  int(1)
>  [1] =3D>
>  int(2)
>  [2] =3D>
>  int(3)
> }
>=20
> whereas in PHP 5.6 and earlier, this produces
>=20
> array(3) {
>  [0] =3D>
>  int(2)
>  [1] =3D>
>  int(4)
>  [2] =3D>
>  int(6)
> }
>=20
> what scares me about this is that in order to get the old behaviour in =
PHP7
> back, you just have to get rid of the ?: operator:
>=20
> foreach($b as &$v){
>=20
> is fine
>=20
> foreach($b ?: [] as &$v){
>=20
> is not.
>=20
> I guess this is related to
> =
http://php.net/manual/en/migration70.incompatible.php#migration70.incompat=
ible.foreach.by-value
> or
> =
http://php.net/manual/en/migration70.incompatible.php#migration70.incompat=
ible.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.
>=20
> Philip
>=20
>=20
>=20
> --=20
> Sensational AG
> Giessh=C3=BCbelstrasse 62c, Postfach 1966, 8021 Z=C3=BCrich
> Tel. +41 43 544 09 60, Mobile  +41 79 341 01 99
> info@sensational.ch, http://www.sensational.ch


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