Collisions with library and variables?

[eluser]Seppo[/eluser]

What if I load a library name category in a controler. This will be accessible with $this->category;

YEs

What if I have a class variable within that controller with the same name category, what would happen?

When you load the library, it will overwrite the variable value... probably not a good idea.
I've done it once with a model named address and another model named user with an address attribute...