Not able to extract exact phrase from the sentence in R

Question

I am trying to extract exact phrase from the sentences in R. It is also extracting the sentence where its is partial matching. Example:

  phrase <- c("r is not working","roster is not working")
  sentence <- c("ABC is not working and roster is not working","CDE is working but printer is not working")

  extract <- sapply(phrase, grepl, x = sentence)
  extract

It gives the output as:

              r is not working      roster is not working
  [1,]             TRUE                  TRUE
  [2,]             TRUE                 FALSE

My desired output is:

              r is not working      roster is not working
  [1,]               FALSE                  TRUE
  [2,]               FALSE                  FALSE

phrase "r is not working" should not match with both sentences. Is there any way to deal with this. Any thoughts? Thanks!!

Answer 1

grepl evaluates regular expressions.

If you want to stick with those, anchor your search patterns to the start and end of string:

phrase <- c("^r is not working$", "^roster is not working$")

If you instead want to check for exact matches, simply use

extract <- sapply(sentence, `%in%`, phrase)