1. Learn
    2. /
  2. Courses
    3. /
  3. String Manipulation with stringr in R

Exercise

Changing case to ease matching

A simple solution to working with strings in mixed case, is to simply transform them into all lower or all upper case. Depending on your choice, you can then specify your pattern in the same case.

For example, while looking for "cat" finds no matches in the following string,

x <- c("Cat", "CAT", "cAt") 
str_view(x, "cat")

transforming the string to lower case first ensures all variations match.

str_view(str_to_lower(x), "cat")

See if you can find the catcidents that also involved dogs. You'll see a new rebus function called whole_word(). The argument to whole_word() will only match if it occurs as a word on its own, for example whole_word("cat") will match cat in "The cat " and "cat." but not in "caterpillar".

A character vector of cat-related accidents has been pre-defined in your workspace as catcidents.

Instructions 1/3

undefined XP
    1
    2
    3
  • Create a pattern to match "DOG" as a whole word using whole_word(), assigning the result to whole_dog_pattern.
  • View the matches to whole_dog_pattern in the original mixed case catcidents.