note 90327 added to language.expressions

Note that even though PHP borrows large portions of its syntax from C, the ',' is treated quite differently. It's not possible to create combined expressions in PHP using the comma-operator that C has, except in for() loops. Example (parse error): <?php $a = 2, $b = 4; echo $a."\n"; echo $b."\n"; ?> Example (works): <?php for ($a = 2, $b = 4; $a < 3; $a++) { echo $a."\n"; echo $b."\n"; } ?> This is because PHP doesn't actually have a proper comma-operator, it's only supported as syntactic sugar in for() loop headers. In C, it would have been perfectly legitimate to have this: int f() { int a, b; a = 2, b = 4; return a; } or even this: int g() { int a, b; a = (2, b = 4); return a; } In f(), a would have been set to 2, and b would have been set to 4. In g(), (2, b = 4) would be a single expression which evaluates to 4, so both a and b would have been set to 4. ---- Server IP: 217.160.72.57 Probable Submitter: 91.32.95.205 ---- Manual Page -- http://www.php.net/manual/en/language.expressions.php Edit -- https://master.php.net/note/edit/90327 Del: integrated -- https://master.php.net/note/delete/90327/integrated Del: useless -- https://master.php.net/note/delete/90327/useless Del: bad code -- https://master.php.net/note/delete/90327/bad+code Del: spam -- https://master.php.net/note/delete/90327/spam Del: non-english -- https://master.php.net/note/delete/90327/non-english Del: in docs -- https://master.php.net/note/delete/90327/in+docs Del: other reasons-- https://master.php.net/note/delete/90327 Reject -- https://master.php.net/note/reject/90327 Search -- https://master.php.net/manage/user-notes.php