chars <- strsplit(rquote, split = "")[[1]] in R Language

Question

rquote <- "r's internals are irrefutably intriguing"
chars <- strsplit(rquote, split = "")[[1]] 

in the above line of code, what's the meaning of [[1]] ?

Answer 1

The enforced [[1]] is a price you pay for generality. Consider this:

R> rquote <- c("R is cool", "But makes you wonder")
R> chars <- strsplit(rquote, split = "")
R> str(chars)
List of 2
 $ : chr [1:9] "R" " " "i" "s" ...
 $ : chr [1:20] "B" "u" "t" " " ...
R> 

So for input that is more than just one object, we get a list back with one list element per input. And for consistency it is the same on a single input: we get a list containing only one element. And [[1]] picks up that element.