Javascript’s regular expression library is becoming world class, guaranteeing that the odd little pattern language will likely be around for generations to come.

So I'm working with Cypress and I'm attempting to understand how to verify a URL via regex matching; but I want to use several character sets in the regex, and I want to add a variable as well ...

Regular expressions are great for converting preformatted text into a different format. Let’s say someone gives you a tab-delimited text file containing items you need to place in an HTML table.