#41375 [Opn->Bgs]: substr() undocumented behavior change from 5.2.1 to 5.2.2

ID: 41375 Updated by: sean@php.net Reported By: bugs dot php dot net at kreidenweis dot com -Status: Open +Status: Bogus Bug Type: Documentation problem Operating System: Any PHP Version: 5.2.2 New Comment: As far as I can tell, this has been documented since at least 2002. The fact that it worked up until 5.2.1 doesn't mean that you should have used it. From the docs: """If string is less than or equal to start characters long, FALSE will be returned.""" http://cvs.php.net/viewvc.cgi/phpdoc/en/reference/strings/functions/substr.xml?revision=1.1&view=markup S Previous Comments: ------------------------------------------------------------------------ [2007-09-07 17:25:21] chagenbu@php.net I should have specified that sometimes you only want the last X characters of a string. That's what this is about. ------------------------------------------------------------------------ [2007-09-07 16:10:25] tony2001@php.net >if (strlen($string) > 16)) > $shorter = substr($string, -16); >else > $shorter = $string; $shorter = substr($string, 0, 16); Please don't tell me you didn't know that. ------------------------------------------------------------------------ [2007-09-07 15:50:42] chagenbu@php.net Alright, here's the use case: I have a string. I want at most 16 characters of it. For all PHP versions before 5.2.[2 or 3], I could do this: $shorter = substr($string, -16); Now I have to do this: if (strlen($string) > 16)) $shorter = substr($string, -16); else $shorter = $string; My question is, especially since I'm asking that the historical behavior of PHP be maintained, how does this change improve the language? What is the point of it? ------------------------------------------------------------------------ [2007-09-07 15:36:40] tony2001@php.net I don't think it's good idea to change it in every release back and forth. Also the current behavior makes much more sense to me. Negative string length is a nonsense, so false is the correct result. ------------------------------------------------------------------------ [2007-09-07 15:12:40] chagenbu@php.net Yes, of course it should have been caught in the RC stage, but it wasn't - in fact it took me more than one final release to track it down. Why is what's done, done, when the behavior that was changed existed for years and years, and the new behavior has been around for 2 point releases? ------------------------------------------------------------------------ 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/41375 -- Edit this bug report at http://bugs.php.net/?id=41375&edit=1