Question

What is the return type of the millis() function?

(a) Signed Long

(b) Unsigned Long

(c) Signed Float

(d) Unsigned Int

I got this question during an online interview.

My question is based upon Time Functions in section Arduino Programming of Arduino

Answer 1

Correct answer is (b) Unsigned Long

To explain: The millis() function gives the up-time or the time since the Arduino started to run the program. The return type here is unsigned long, which means basically a number of the long datatype without any plus or minus signs. This number denotes the up time in milliseconds.