#42256 [Opn]: PHP4 backwards-compatibility slightly broken

ID: 42256 User updated by: mat at bcclimited dot co dot uk Reported By: mat at bcclimited dot co dot uk Status: Open Bug Type: Documentation problem Operating System: Windows, Linux PHP Version: 5.2.4RC1 New Comment: I wouldn't say "clearly"... It kind of makes sense the way PHP4 works, and I'd expect that any features that claim to be backwards-compatible work in the same way as the old version, else the claim is fallacious. I assume that the PHP4 interpreter looks at all available functions for one matching the class name and calls it if it exists, whereas PHP5 only looks in the functions implemented in that class and does not traverse up to the parent - making it behave as if the function was not inherited. I take it this is a "will not fix"/"not broken" status, and I need to recode all the classes that are constructed like this? :( Previous Comments: ------------------------------------------------------------------------ [2007-08-10 01:25:42] judas dot iscariote at gmail dot com Interesting ;) the documentation should also mention that the old PHP4 beahviuor is clearly the wrong thing. ------------------------------------------------------------------------ [2007-08-09 15:01:28] jani@php.net Reclassified. ------------------------------------------------------------------------ [2007-08-09 13:40:03] mat at bcclimited dot co dot uk Nuts, typo. Both the Users should start: class Users extends users_base { ------------------------------------------------------------------------ [2007-08-09 13:26:22] mat at bcclimited dot co dot uk Oh, thought I'd add a workaround: class Users { function Users() { parent::Users(); } } Unfortunately for me, there are one hell of a lot of classes that our previous programmer built in this fashion, making the workaround impractical. ------------------------------------------------------------------------ [2007-08-09 13:22:18] mat at bcclimited dot co dot uk Description: ------------ PHP4-style constructors do not function, in PHP5, in the same way as they do in PHP4. The issue lies in when parent constructors are called, or not as the case may be. Reproduce code: --------------- class users_base { function Users() { echo "users_base::Users()\n"; } } class Users { // Nothing here. } $base = new users_base(); $child = new Users(); Expected result: ---------------- Running the sample code in PHP4 will give the expected result: users_base::Users() users_base::Users() Whereas PHP5 will not call the Users() function in the parent class: users_base::Users() I class this as a bug because of the expected PHP5 behaviour as well as the evident PHP4 behaviour. If the users_base function is renamed to __construct(), it will get called on BOTH instantiations, as PHP4 does with its style. Actual result: -------------- users_base::Users() (The child class does not call Users() on instantiation) ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=42256&edit=1