/^[a-z0-9_-]{3,16}$/

Eugene Kudashev

Comment

Regular expressions can be extremely useful whenever you need to make the computer do something with text. For example, when you need to check that what user typed is a real email, or automatically replace every uppercase letter F into a lowercase letter F. But as useful as they are, regular expressions can be extremely confusing and intimidating for beginners. In this podcast I’m going to explain regular expressions in a simple and accessible way, and help you start using them in your day-to-day work.