#19146 [Opn->Bgs]: Old Value kept after unset() on a &$parameter inside function.

ID: 19146 Updated by: iliaa@php.net Reported By: purodha.blissenbach@hostsharing.net -Status: Open +Status: Bogus Bug Type: Scripting Engine problem Operating System: Linux, diverse Debian PHP Version: 4.1.2 New Comment: Thank you for taking the time to write to us, but this is not a bug. Please double-check the documentation available at http://www.php.net/manual/ and the instructions on how to report a bug at http://bugs.php.net/how-to-report.php unset() destroyes the $byname variable, so when it is re-created in the function it is no longer 'attached' to the $byname that is passed by reference to the function. Instead it is now a local variable inside that function. Previous Comments: ------------------------------------------------------------------------ [2002-08-28 09:17:08] purodha.blissenbach@hostsharing.net unset()ting a variable passed by reference does not destroy this variable, but rather protects it's value against being further altered inside the function. < ? php function subroutine(&$byname, $assign, $unset) { if($assign) $byname = 'set by subroutine'; if($unset) unset($byname); $byname = 'finally set inside subroutine'; } $byname = 'Set Outside!'; subroutine($byname, TRUE, FALSE); echo ('<p> 1st. call: ($assign=TRUE, $unset=FALSE) returns $byname="'.$byname.'"</p>'); $byname = 'Set Outside!'; subroutine($byname, FALSE, FALSE); echo ('<p> 2nd. call: ($assign=FALSE, $unset=FALSE) returns $byname="'.$byname.'"</p>'); $byname = 'Set Outside!'; subroutine($byname, TRUE, TRUE); echo ('<p> 3rd. call: ($assign=TRUE, $unset=TRUE) returns $byname="<b>'.$byname.'</b>"</p>'); $byname = 'Set Outside!'; subroutine($byname, FALSE, TRUE); echo ('<p> 4th. call: ($assign=FALSE, $unset=TRUE) returns $byname="<b>'.$byname.'"</p></b>'); ? > Outputs: 1st. call: ($assign=TRUE, $unset=FALSE) returns $byname="finally set inside subroutine" 2nd. call: ($assign=FALSE, $unset=FALSE) returns $byname="finally set inside subroutine" 3rd. call: ($assign=TRUE, $unset=TRUE) returns $byname="set by subroutine" 4th. call: ($assign=FALSE, $unset=TRUE) returns $byname="Set Outside!" More information and a live Demo can be obtained from http://purodha.hostsharing.de/hostsharing/menu0/test_by_name.php ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/?id=19146&edit=1