There are many programming questions in Arduino (there is even a tag for it). However, some are not related to Arduino, like
There is a flag/close/offtopic because/This question belongs on another site in the Stack Exchange network option, but StackOverflow is not mentioned as possible candidate.
So far I flag the question and ask a moderator to move, but what is the preferred solution?
Just closing down the question, seems also not useful, especially if it can be answered while it is in Arduino StackExchange (even though it will be moved preferably).