## Introduction to regular expressions

## Basic idea

A regular expression is a notation to represent standards in strings. It serves to validate data entries or to search and extract information in texts

It is just a series of characters which define an abstract search pattern. In a nutshell, most search engines perform such functions as search for specific words, phrases, and webpages, or find and replace operations on text. Essentially, it is a mathematical technique developed by formal language and computer science experts.

The process of generating the patterns can be a complex algorithm based on mathematical principles. A Regex is simply a string containing …