I have seen many tutorials on programming an Arduino to control a HC-05 bluetooth module. In that I did not understand the term called 'flag'. What does that mean?

  • 3
    And what is the context of this word?
    – Majenko
    Commented Apr 22, 2016 at 15:09
  • 1
    "Flag" is usually a feature that you can turn on or off. The "flag" is the variable that you need to use to do that. But as Majenko stated, with no context, it's just a guess I am taking here.
    – fabrosell
    Commented Apr 22, 2016 at 15:10

1 Answer 1


I've always used flag to indicate a boolean logic value. I would also suggest this is an archaic term.

Was going to come up with my own explanation but found the following at In C language, what does flag mean?:

A 'flag' is a variable that is supposed to signalize something. Think about the word itself - flags are used in sending signals. In our world of programming a basic boolean flag can either be "up" or "down", either true or false.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.