# semicolon terminator for switch cases - Thread: https://externals.io/message/109350 - Original archive: https://news-web.php.net/php.internals/109350 - Started by Ilija Tovilo on 2020-03-26T18:37:07+00:00 - Messages: 10 - RFC: Deprecations for PHP 8.5 (Implemented (PHP 8.5)) — https://externals.io/rfc/deprecations_php_8_5.md - Reply by email to internals@lists.php.net - More for agents: search with https://externals.io/search.md?q={query} · RFCs at https://externals.io/rfc.md · JSON API at https://externals.io/api · documentation at https://externals.io/llms.txt --- ## #109350 — Ilija Tovilo — 2020-03-26T18:37:07+00:00 URL: https://externals.io/message/109350#109350 Hi internals Looking through the language grammer I discovered that switch cases can also be terminated with a `;` instead of a `:`. ``` switch ($i) { case 1; return 1; default; return 2; } ``` https://3v4l.org/o7nD8 This is in fact documented: https://www.php.net/manual/en/control-structures.switch.php What's the reasoning behind this? I find it weird an inconsistent. Maybe something to deprecate in PHP 8.0. https://wiki.php.net/rfc/deprecations_php_8_0 Regards --- ## #109356 — Stanislav Malyshev — 2020-03-26T20:14:14+00:00 URL: https://externals.io/message/109350#109356 · In reply to: #109350 Hi! > Maybe something to deprecate in PHP 8.0. > https://wiki.php.net/rfc/deprecations_php_8_0 Why? Whose life it'd make easier? -- Stas Malyshev smalyshev@gmail.com --- ## #109357 — David Rodrigues — 2020-03-26T20:26:13+00:00 URL: https://externals.io/message/109350#109357 · In reply to: #109356 I agree with Tovilo. It is weird and confusing. Actually I never know that it was possible. And the ";" sounds like "it ends here", while ":" counds like "it does it ->". For me, "case 1;" will sounds like "skip case 1". Atenciosamente, David Rodrigues Em qui., 26 de mar. de 2020 às 17:14, Stanislav Malyshev < smalyshev@gmail.com> escreveu: > Hi! > > > […] > > Why? Whose life it'd make easier? > > -- > Stas Malyshev > smalyshev@gmail.com --- ## #109358 — Stanislav Malyshev — 2020-03-26T20:28:38+00:00 URL: https://externals.io/message/109350#109358 · In reply to: #109357 Hi! > I agree with Tovilo. It is weird and confusing. Actually I never know > that it was possible. You seem to contradict yourself - if you never knew it was possible, how could you ever be confused by it? -- Stas Malyshev smalyshev@gmail.com --- ## #109359 — Benoit SCHILDKNECHT — 2020-03-26T20:49:30+00:00 URL: https://externals.io/message/109350#109359 · In reply to: #109358 Le Thu, 26 Mar 2020 21:28:38 +0100, Stanislav Malyshev a écrit: > Hi! > > > > […] > > You seem to contradict yourself - if you never knew it was possible, how > could you ever be confused by it? > OK, I'm often lurking, but I have to react to this. I never knew it was possible too, but I am also confused by this. A semi-colon is terminal. It always is. "You see this set of instructions? Done.". But in this case, it is not. You see the problem? -- L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast. https://www.avast.com/antivirus --- ## #109362 — Claude Pache — 2020-03-26T21:30:22+00:00 URL: https://externals.io/message/109350#109362 · In reply to: #109359 > Le 26 mars 2020 à 21:49, Benoit SCHILDKNECHT a écrit : > > A semi-colon is terminal. Italways is. "You see this set of instructions? Done.". But in this case, itis not. You see the problem? > No I don’t see the problem. Inside a switch construct, when you reach the end of an instruction (or of a set of instructions) that is not (resp. does not end with) a control-flow statement, you pass to the next one. I’m sure that everybody knows that you have to use an explicit control-flow statement like “break” or “return” if you want to be “done” before reaching the bottom of the switch construct. Or maybe people could misguess that “;” in that context is an odd way to mean “: break;”? —Claude --- ## #109363 — Claude Pache — 2020-03-26T22:04:34+00:00 URL: https://externals.io/message/109350#109363 · In reply to: #109350 > Le 26 mars 2020 à 19:37, Ilija Tovilo a écrit : > > What's the reasoning behind this? I find it weird an inconsistent. > This is a manifestly a leftover of an old syntax. Take a look at the PHP/FI 2 manual: Language constructs: https://www.php.net/manual/phpfi2.php#lang ``` ``` and, in particular, switch construct: https://www.php.net/manual/phpfi2.php#switch ``` ``` Note that every line of code, including `if (...);` and `case...;`, is consistently terminated by a semicolon. In a subsequent major version, the syntax was modified, and you would use a colon instead of a semicolon in a number of places, as you can write today: ``` ``` Although the old `if (true);` syntax has been removed (probably because of ambiguity or difficulty of parsing), the old `case 1;` syntax could be left without issue. —Claude --- ## #109364 — Andrea Faulds — 2020-03-26T22:07:40+00:00 URL: https://externals.io/message/109350#109364 · In reply to: #109350 Hi Ilija, Ilija Tovilo wrote: > Looking through the language grammer I discovered that switch cases can also be terminated with a `;` instead of a `:`. > > ``` > switch ($i) { > case 1; > return 1; > default; > return 2; > } > ``` > > https://3v4l.org/o7nD8 > > This is in fact documented: > https://www.php.net/manual/en/control-structures.switch.php > > What's the reasoning behind this? I find it weird an inconsistent. For whatever reason, I somehow remember that this dates to at least PHP/FI 2.0, which means it's as least as old as me (24 years… no, I was not involved with PHP back then ;). And indeed, the case statement is mentioned in the manual (https://www.php.net/manual/phpfi2.php#lang), with an example to be found in https://museum.php.net/php2/php-2.0.tar.gz under php-2.0/test/lang/003.tst: --TEST-- Simple Switch Test ... --POST-- --GET-- --FILE-- --EXPECT-- Content-type: text/html good Being able to use a colon instead of a semicolon here is, I guess, a more modern thing. Was it PHP 3 or PHP 4 that changed this? Who knows. I don't think it's hurting anyone as it is… can we leave it in peace? :) Thanks, Andrea --- ## #109365 — Christoph M. Becker — 2020-03-26T22:38:43+00:00 URL: https://externals.io/message/109350#109365 · In reply to: #109363 > > […] > > This is a manifestly a leftover of an old syntax. Take a look at the PHP/FI 2 manual: > > Language constructs: > https://www.php.net/manual/phpfi2.php#lang > > > ``` > if($a==5 && $b!=0 ); > $c = 100 + $a / $b; > endif; > > […] > ``` > > and, in particular, switch construct: > https://www.php.net/manual/phpfi2.php#switch > > ``` > $a=0; > switch($a) { > case 1; > echo "a is 1"; > break; > case "hello"; > echo "a is hello"; > break; > default; > echo "a is unknown"; > break; > } > > […] > ``` > > Note that every line of code, including `if (...);` and `case...;`, is consistently terminated by a semicolon. > > In a subsequent major version, the syntax was modified, and you would use a colon instead of a semicolon in a number of places, as you can write today: > > ``` > if ($a==5 && $b!=0): > $c = 100 + $a / $b; > endif; > > […] > ``` > > Although the old `if (true);` syntax has been removed (probably because of ambiguity or difficulty of parsing), the old `case 1;` syntax could be left without issue. Interesting! Thanks for digging this out. :) -- Christoph M. Becker --- ## #109370 — Ilija Tovilo — 2020-03-27T11:01:19+00:00 URL: https://externals.io/message/109350#109370 Hi Andrea The reason this doesn't work anymore: ``` If (false); echo 'Test'; endif; ``` Is because the semicolon is an empty statement: https://github.com/php/php-src/blob/9e77d5a9da9e80a1bfe226f60ccb12fd8bf9481c/Zend/zend_language_parser.y#L457 This is still valid code: ``` If (false); echo 'Test'; ``` And it always prints. The two semicolons look the same but behave differently which is why I'm in favor of deprecating it. Regards