This tutorial is a quick-reference for common regular expressions, or regex, components, and how to use them.
Regular expressions are used to validate input by searching for (matching) specific patterns in a given string. This is helpful in many applications, such as to check if an email input is the correct format of an email, or if a user enters a URL that matches the correct format of a URL, etc.
Although they may seem confusing at first, with practice they become easy to work with and can be very powerful in making your code less succeptible to user error.