Functional programming doesn’t mean no side effects though. At some point, every language/platform has to have them, or it can’t be used for dynamic inputs. Re

Functional programming doesn’t mean no side effects though. At some point, every language/platform has to have them, or it can’t be used for dynamic inputs. React (can) have referential transparency and up to a degree immutability (yes hooks are not side effect free, but so isn’t the IO monad).