Internal Pull Up advice

I think I've got my head round using the internal pull up resistors on the 328 chip rather than external pull down ones, my sketch works as expected with the pull ups deployed for 6 switches anyway.

I just wanted clarification on one issue though if someone with a little more experience could oblige.

I used the info on this link:

And i'm just a little confused by:

The analogRead command will not work correctly if a pin has been previously set to an output, so if this is the case, set it back to an input before using analogRead. Similarly if the pin has been set to HIGH as an output, the pullup resistor will be set, when switched back to an input.

I understand that the pin would need switching back to an input and the pull up will need turning off beofre reading any values but is this talking about in the SAME sketch or a DIFFERENT sketch?

ie if I upload a totally different sketch on the same chip do I need to explicitly make these changes?


It means if it has been changed within the current sketch. Following a reset or reprogramming, everything reverts to defaults.

Thanks, that makes sense