Serial.print without screen

Hello, I am new to arduino. I don't even own one yet. So I'd like to ask: what happens if I use Serial.print, without having a screen on my arduino?

it will send the appropriate bit pattern over the line but there is no one to receive so the signal will be "gone"

So basically nothing happens, that is also nothing bad either.

The picturesque technical phrase for this is the bytes are "dropped on the floor".

I have heard the phrase, "the signal went to the eternal electric fields"

Thank you very much! I just wanted to know before start coding...

The picturesque technical phrase for this is the bytes are "dropped on the floor".

Technically the bytes are not necessarily dropped on the floor.
Assuming a UART serial port is being used,
all bytes are still handed to the Serial class which buffers them and sends them out the UART
since with only TX and RX UART serial signals, there is no way to tell if there is a listener.
If the TX buffer fills, the sketch will be paused/blocked while the Serial class library
is waiting on the data to exit the UART to make room in the TX buffer.

For boards like Teensy and Leonardo, I think if the USB host is not attached
the bytes are thrown away (dropped on the floor) since the USB code
can tell there is no host.

Didn't realise there was a hardware/software distinction - my copy of the
New Hackers' Dictionary doesn't clarify the semantics :slight_smile:

It just means silently lost. No error reported.

The only reason I mentioned it was because from a timing perspective it makes a difference
where the characters are dropped/lost.
i.e. on a real UART it could still affect the timing since the characters are still being sent out
the wires and will block the application if it sends too many characters too quickly
whereas on something with native USB like Teensy, it will figure out that there is no host and will
drop the characters without the transmission overhead.

--- bill