Regular expressions are common in the programming world as a way of finding (and filtering) text based on patterns. regexes can range from extremely simple, such as the example above for finding whitespaces, to longer expressions for more general inputs. If you are one of the wizards who can actually comprehend phrases like (?<=^|(?<=[^a-zA-Z0-9-_\.]))@([A-Za-z]+[A-Za-z0-9]+) (a regex for identifying Twitter usernames), then Google Docs' latest feature is just for you.

Starting today on Google Docs on the web, although not yet on mobile, regex expressions are supported in the Find and Replace dialog. You can use regexes in both the Find and Replace with fields, and as long as they match RE2 syntax, they should work. It is worth noting that Microsoft Office, perhaps the most direct competitor to Google Docs, only supports Microsoft's own wildcard syntax.

No option to enable Regexes on Docs for Android yet.

No option to enable Regexes on Docs for Android yet.

You should see the changes already live, but Google's blog post mentions they may take another two days to appear for everyone. If you want to brush up on regular expressions, Google has created a help document with some general information and examples.