Removing duplicate words in a string in R

Question

Just to help someone who\'s just voluntarily removed their question, following a request for code he tried and other comments. Let\'s assume they tried something like this:

Answer 1

There are no need additional package

str <- c("How do I best try and try and try and find a way to to improve this code?",
         "And and here's a second one one and not a third One.")

Atomic function:

rem_dup.one <- function(x){
  paste(unique(tolower(trimws(unlist(strsplit(x,split="(?!')[ [:punct:]]",fixed=F,perl=T))))),collapse = " ")
}
rem_dup.one("And and here's a second one one and not a third One.")

Vectorize

rem_dup.vector <- Vectorize(rem_dup.one,USE.NAMES = F)
rem_dup.vector(str)

REsult

"how do i best try and find a way to improve this code" "and here's a second one not third"