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

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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 = "___$")

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