Add a space every three characters from the end

Question

I need to add a space between every 3rd character in the string but from the end. Also, ignore the element, which has a percentage %.

string <- c('186527500', '3875055', '23043', '10.8%', '9.8%')

And need to get the view: 186 527 500, 3 875 055, 23 043, 10.8%, 9.8%

Answer 1

You could do:

ifelse(grepl('%', string), string, scales::comma(as.numeric(string), big = ' '))
#> [1] "186 527 500" "3 875 055"   "23 043"      "10.8%"       "9.8%"