reserved variable names

[eluser]Unknown[/eluser]
in codeigniter as per the user guide $config,$lang etc are reserved variable names.

i tried using these variables and i didn't see any issues. could you show by an example as to how and when using these reserved variable names will cause an issue?

[eluser]keevitaja[/eluser]
it depends, where you use them. if you are using $config in method or function, without declaring it to be global, then they are not global scope...

http://php.net/manual/en/language.variables.scope.php

[eluser]skunkbad[/eluser]
Knowing that they are reserved, you should try to avoid using them, as they could cause conflicts and produce very hard to track down bugs. One time I did have a problem using the variable $output, which I believe is a reserved variable name. I don't recall exactly what I did, but I don't do user $output anymore.