stringr function to concatenate vector of words separated by comma with “and” before last word

Question

I know I can easily write one, but does anyone know if stringr (or stringi) already has a function that concatenates a vector of one or more words separated by commas, but with

Answer 1

You can use the knitr::combine_words function

knitr::combine_words(letters[1:2])
# [1] "a and b"
knitr::combine_words(letters[1:3])
# [1] "a, b, and c"
knitr::combine_words(letters[1:4])
# [1] "a, b, c, and d"