Setting an option to NULL

Question

Is it possible to set an options to NULL while using getOption with a default value other than NULL?

options("TEST" = NULL)
getOption("TEST")
# NULL

getOption("TEST", default=1)
# [1] 1

I would have expected the last line to return NULL. Is this intended behavior.

score 2 · Answer 1 · answered Jul 21 '14 at 15:29

2

options is a named list, so setting an option to NULL is akin to removing that option.

It appears there is no way to have an option set to NULL while also allowing the use of getOption with an alternate default value.

answered Jul 21 '14 at 15:29

Ricardo Saporta

score 2 · Accepted Answer · answered Jul 21 '14 at 15:41

2

Workaround: nest the (potentially NULL) value in a list and use that:

options(TEST = list(NULL))
getOption("TEST")[[1]]
# [1] NULL

getOption("TEST", default = list(1))[[1]]
# [1] NULL

answered Jul 21 '14 at 15:41

Konrad Rudolph

You can see my comment on a deleted post, correct? Just wanted to make sure. – Rich Scriven Jul 21 '14 at 23:36
1

@richard Yes, I do. I appreciate the fact that you replied at all, by the way. :-) – Konrad Rudolph Jul 21 '14 at 23:48
Oh, absolutely. I appreciate you commenting and giving me a chance to do something first, rather than just logging a downvote. I'm here to learn and (hopefully) help others at the same time. – Rich Scriven Jul 22 '14 at 02:33
Thanks Konrad for the answer. This might be the best workaround, but I do hate littering my code with a slew of `[[1]]` -- although I'm not sure if there is any other way – Ricardo Saporta Jul 25 '14 at 05:25
@Ricardo Well you’d wrap it into a function, of course. Something like `getNullableOption` – Konrad Rudolph Jul 25 '14 at 08:09
@Konrad, In fact, exactly what I did. Thanks again – Ricardo Saporta Jul 29 '14 at 19:39

2 Answers2