I am terrible with arrays. I usually end up get long if - then - else codes.
The values which change need to show either at p01 or p02 position.
Value can lower or higher. I think some sort of "when" function.
when value changes - then print 
hahaha... the principe is clear, but how to write it down is the issue.
could you recommend a good way of learning?
should I buy a book or how can i learn the best way?
I usually search for youtube tutorials about whatever I need to do, get the code and then adjust it to my needs. This works mostly fine, until it gets more individual.