In the ‘row’ example there is nothing alphanumeric about the string, so using ‘(\w+)’ behooves me to seek clarity. Can ‘[a-z]+’ also be a reference? Is it still permissible to use ‘(\w+)’, despite it’s alphabetical nature?
You need to include the link to the challenge so we know which one you are talking about.
If you know that the words in the string you are searching will only ever have the letters a-z then yes, you could use
([a-z]+). But this example doesn’t make that assumption, so it uses
(\w+) to catch a broader range of characters.