#41228 [Opn->Csd]: Side-effects for logical operators

ID: 41228 Updated by: colder@php.net Reported By: terminatorul at gmail dot com -Status: Open +Status: Closed Bug Type: Documentation problem PHP Version: Irrelevant -Assigned To: +Assigned To: colder New Comment: This bug has been fixed in the documentation's XML sources. Since the online and downloadable versions of the documentation need some time to get updated, we would like to ask you to be a bit patient. Thank you for the report, and for helping us make our documentation better. Previous Comments: ------------------------------------------------------------------------ [2007-04-30 12:03:44] arpad@php.net My point was that the term "short-circuit" is already mentioned twice on the page, if you didn't know what it meant in this context then a google search for "short-circuit operator" would yield a page full of relevant results. Of course it could be spelled out in the text, but even if I was in favour of doing so, I don't have phpdoc karma. That's why I just stated my opinion and left the bug open. ------------------------------------------------------------------------ [2007-04-30 11:50:08] terminatorul at gmail dot com My point exactly. A programing language may or may not guarantee side-effects from evaluation of operands to logical operators. Or at least would say that it is undefined if the side-effect occurs. The proffesional C++ programmer will find it normal for the language to shortcut the expression, while a beginner will not understand what's wrong with his/her code. ------------------------------------------------------------------------ [2007-04-30 11:44:35] rquadling@php.net Good ole MS! http://support.microsoft.com/kb/817250 ------------------------------------------------------------------------ [2007-04-30 11:42:27] rquadling@php.net Two opposing thoughts. Delphi - http://info.borland.com/techpubs/delphi/delphi5/oplg/syntlmnt.html#10548 In Delphi, shortcut/short-circuit is optional, though as standard it is enabled. VB - http://www.informit.com/guides/content.asp?g=dotnet&seqNum=480&rl=1 Seemingly VB does NOT have a short circuit. Who do you believe. For the seasoned programmer, this is perfectly obvious. But if you're upgrading your skill set from, say, VB, then this REALLY odd behaviour is completely new. And what debugging would you provide? This should be documented and probably in several places as there are many references to boolean logic throughout the manual. It is the LACK of documentation on this standard feature within PHP that is the issue. ------------------------------------------------------------------------ [2007-04-30 10:08:31] arpad@php.net This isn't a side-effect, but an intrinsic property of these operators. As two out of the four user notes on the page mention, the first dating back to 1999, these operators short-circuit. Perhaps this could be explained in the text to make it clearer for people new to programming, but I don't think there's any great need; I assume most people can look up terms they're not familiar with. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at http://bugs.php.net/41228 -- Edit this bug report at http://bugs.php.net/?id=41228&edit=1