Edit report at https://bugs.php.net/bug.php?id=40880&edit=1
ID: 40880 Updated by: ras...@php.net Reported by: prometheus__0 at hotmail dot com Summary: public->protected inheritance causes fatal Status: Not a bug Type: Bug Package: Class/Object related Operating System: SUSE SLES 10 PHP Version: 5CVS-2007-03-21 (snap) Block user comment: N Private report: N New Comment: Most (all?) object oriented languages work this way. Java and C# both do. You can loosen visibility when you override a parent method, but you can never tighten it. This is part of what is known as the Liskov Substitution Principle and it is one of the fundamental principles of object oriented programming. You can read about at http://en.wikipedia.org/wiki/Liskov_substitution_principle I can guarantee that abiding by LSP is not a bug Previous Comments: ------------------------------------------------------------------------ [2012-05-06 15:40:26] ekincigokan at gmail dot com Same "problem". class A{ public function __construct(){} } class B extends A { protected function __construct(){} } Please, can you tell us a reason why we can't put an private/protected access to B's constructor if A's constructor is public ? Is there any logical reason to this ? Thanks. ------------------------------------------------------------------------ [2011-09-10 22:27:24] herman dot wetherington at gmail dot com Apparently, we don't call this a "bug" because this is not caused by a programming error. So I'm calling it a "massive design flaw" instead. ------------------------------------------------------------------------ [2010-10-15 23:33:35] robertoblanko at gmail dot com Same problem here. You cannot actually apply the singleton pattern to subclasses with this behavior. I do not see any reason for not calling this a bug. ------------------------------------------------------------------------ [2010-09-07 12:58:35] nickyla83 at yahoo dot fr I'm in the same situation as our friend "prometheus" here, I am trying to use a singleton pattern and logically, this should involve being able to encapsulate the subcalasses information particularly setting up a private constructor for the singleton subclass, IT DEFINITELY DOES MAKE SENSE, so please try to take this under consideration for the next php engine release. ------------------------------------------------------------------------ [2007-03-21 10:05:25] prometheus__0 at hotmail dot com is this the 'php'-dev definition? i'm asking cause wraping a singleton pattern around a subclass makes sense and the same example is valid for java and c++ to ask it differently: why is it working this way in php? (i'm interested in the background of this) my point is that 2 languages allow it and there is an example which is valid, not? ------------------------------------------------------------------------ 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 https://bugs.php.net/bug.php?id=40880 -- Edit this bug report at https://bugs.php.net/bug.php?id=40880&edit=1
