without any doubt true and correct
Well, they weren't correct.
"Serial.print(' ');" is perfectly valid
No argument there ...
and does what the OP expected.
but the original code was not
a single space between single quotes, so it is difficult to see what the poster expected.
It also begs the question "Why would you want to print a space (or spaces, if that was the intention) immediately before a CR/LF?"
(I'm old enough to remember having to print spaces after
CR/LF, to give the teletype head time to reach the start of the line, but that's a different matter).
So, having raised a few questions about the program writer's state of mind, I ask the simple question "What's that?"
This give the poster time to reflect, and come back with:
"That's not my actual code, it's just what I think I wrote, because I don't have access to the computer it is on right now", in which case I say, "OK, I'll come back later when you've posted the actual code and not some half-remembered nonsense, and I'm not on a wild goose chase", or
"that's not the actual code, it's a scan of a printout of the actual code which I dug out of the wastepaper basket", in which case I say "OK, I'll come back later when you've posted the actual code and not some transcription-error-riddled nonsense, and I'm not on a wild goose chase"or
"No, I really don't have clue why I did that" in which case I say, "OK, get rid of the crap, and concentrate on the problems you're having"
"I'm not actually running this on an Arduino because it hasn't arrived yet, so I'm using some simple-minded unsactioned simulator I found on the interwebs".