Get startedGet started for free

If you don't know what you're looking for

So far you've used str_detect() which returns TRUE if the pattern matches and FALSE otherwise. But regular expressions are also excellent at extracting the searched term from a larger amount of text. You can use the str_match() function for that.

The next special character you'll get to know is the period: ".". The period matches any character, it's like a wild card. So if you search for example for "..." you will find three characters - be it letters or numbers or even white spaces.

This is pretty handy, except if you need to search for an actual full stop ".". In that case: escape the period with two backslashes: "\\."

This exercise is part of the course

Intermediate Regular Expressions in R

View Course

Exercise instructions

  • Match not only Saw 4 but also the other sequels.
  • Match the first four characters of all the movie titles that start with "K".
  • Detect the movie that ends with an actual full stop ".".

Hands-on interactive exercise

Have a go at this exercise by completing this sample code.

# Here's an example pattern that will find the movie Saw 4
str_match(movie_titles, pattern = "Saw 4")

# Match all sequels of the movie "Saw"
str_match(movie_titles, pattern = "___")

# Match the letter K and three arbitrary characters
str_match(movie_titles, pattern = "^K___")

# Detect whether the movie titles end with a full stop
str_detect(movie_titles, pattern = "___$")
Edit and Run Code