In my php.ini file I have the error_reporting property set to E_ALL and the display_errors property set to On, but when I use an unassigned variable I do not get an error message back in my web page.
should return a page with a message like:
Notice: Undefined variable: foo in C:\Program Files\xampp\htdocs\\foo.php on line 4
Instead I get a blank page. I restarted Apache after changing the PHP.ini file. If I use the command line or if I use an error_reporting(E_ALL) directive at the top of my PHP code I get the appropriate error message.
Phpinfo() revealed that Apache is using the php.ini file at ...\xampp\apache\bin\php.ini, not the one I changed at ...\xampp\php\php.ini. The one inside the Apache bin folder has the error_reporting property set to E_ALL & ~E_NOTICE, which, of course, prevents the unassigned variable "notice".
I also see the very clear explanation in the XAMPP for Windows FAQ.