If analogue value is constant for Xs then... How do I even start?

[mrburnette]

@at3921

but after a quick check, I now realise that i'm sorely mistaken!

There are several "cheat-sheets" with commands and syntax, find one you like and get it printed for quick reference. One is here:
https://forum.arduino.cc/t/arduino-programming-cheat-sheet/67896