So what is a REGXP?

A regular expression (regex or regexp for short) is a special text string for describing a search pattern. You can think of regular expressions as a powerful searcch or a wildcard on steriods . You are probably familiar with wildcard notations such as .txt to find all text files in a file manager. The regex equivalent is ^..txt$.

Below is an example of some of the special characters in a regular expression

Uses of Regular Expressions

We can use Regular Expressions to search large volumes of text for certain patterns. We can use it to ensure a user enters in the correct data. Regular expressions can be used in virtually any programming language. A knowledge of regex is very useful for validating user input, interacting with the Unix shell, searching/refactoring code in your favourite text editor, performing database text searches, and lots more.

Sources

https://en.wikipedia.org/wiki/Regular_expression

https://blog.patricktriest.com/you-should-learn-regex/

Lecture slides