Is there anything wrong with using T & F instead of TRUE & FALSE?

Question

I noticed that using T and F instead of TRUE and FALSE in functions in R gives me the same results. Of course, T and F are more concise, yet, I see TRUE and FALSE being used more often.

I was wondering whether there is any difference between the two? Is there anything wrong with using T and F?

Answer 1

T and F can be re-defined, but TRUE and FALSE are reserved words and cannot be re-defined.

> TRUE <- 1L
Error in TRUE <- 1L : invalid (do_set) left-hand side to assignment
> FALSE <- 0L
Error in FALSE <- 0L : invalid (do_set) left-hand side to assignment
> T <- F  # yikes, this would be hard to debug!

Personally, I sometimes use T and F when I use R interactively, but I never use them in production code or packages.