November 2019
Beginner to intermediate
592 pages
14h 43m
English

You may be familiar with searching for text by pressing CTRL-F and entering the words you’re looking for. Regular expressions go one step further: they allow you to specify a pattern of text to search for. You may not know a business’s exact phone number, but if you live in the United States or Canada, you know it will be three digits, followed by a hyphen, and then four more digits (and optionally, a three-digit area code at the start). This is how you, as a human, know a phone number when you see it: 415-555-1234 is a phone number, but 4,155,551,234 is not.
We also recognize all sorts of other text ...