capitalize last letter of a single word

Question

In R trying to write a function that takes the word MarsuPial and results in marsupiaL.

current code

mycap <- function(mystr = "") {
  mystr <- tolower(mystr)
  a <- substr(mystr, 1, 1)
  b <- substr(mystr, 2, nchar(mystr))
  paste(tolower(a), b, sep = "")
}

Answer 1

You can use substr<- to capitalise the last character.

mycap <- function(mystr = "") {
  mystr <- tolower(mystr)
  n <- nchar(mystr)
  substr(mystr, n, n) <- toupper(substr(mystr, n, n))
  return(mystr)
}

mycap('MarsuPial')
#[1] "marsupiaL"
mycap('dummy')
#[1] "dummY"