Bug #69921 [Opn->Nab]: function_exists returns true before function definition

Edit report at https://bugs.php.net/bug.php?id=69921&edit=1 ID: 69921 Updated by: cmb@php.net Reported by: alan at aondra dot com Summary: function_exists returns true before function definition -Status: Open +Status: Not a bug Type: Bug Package: Scripting Engine problem Operating System: Any PHP Version: 5.6.10 -Assigned To: +Assigned To: cmb Block user comment: N Private report: N New Comment: Sorry, but your problem does not imply a bug in PHP itself. For a list of more appropriate places to ask for help using PHP, please visit http://www.php.net/support.php as this bug system is not the appropriate forum for asking support questions. Due to the volume of reports we can not explain in detail here why your report is not a bug. The support channels will be able to provide an explanation for you. Thank you for your interest in PHP. According to the documentation[1]: | Functions need not be defined before they are referenced, [...] function_exists() yields a result accoring to this, i.e. where a function can be called, function_exists() returns true. [1] <http://php.net/manual/en/functions.user-defined.php> Previous Comments: ------------------------------------------------------------------------ [2015-06-24 15:10:45] alan at aondra dot com . ------------------------------------------------------------------------ [2015-06-24 14:57:52] alan at aondra dot com Gave a better summary ------------------------------------------------------------------------ [2015-06-24 14:56:19] alan at aondra dot com Description: ------------ --- From manual page: http://www.php.net/function.function-exists --- The function 'function_exists' does not execute in the order in which the code is evaluated. Not only is this wrong, it allows for the possibility that code could be executed in the incorrect scope. I saw this note on the documentation: "A function name may exist even if the function itself is unusable due to configuration or compiling options (with the image functions being an example)." I looked and found no such configuration or compiling option that would allow for this. Test script: --------------- <?php header('Content-Type: text/plain'); $mystr = 'should not execute'; if(function_exists('myfunc')) { myfunc($mystr); } $mystr = 'execute'; function myfunc($str) { die($str); } myfunc($mystr); Expected result: ---------------- execute Actual result: -------------- should not execute ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=69921&edit=1