The Personal Web Pages of Chris X. Edwards Regular Expression Tutorial

WHY USE REGULAR EXPRESSIONS?

Just as simple neurons can be composed into a network with simple rules, yet produce miraculously complex behavior, so too can the seemingly simplistic rules governing regular expressions produce amazingly complex and useful results. Most useful things computers can do involve an interpretation of numerical data into something humans can understand. When dealing with large amounts of data, there is often a need to have that data manipulated while it is in a human readable form, i.e. text strings. This kind of operation is fundamental to computer usefulness.

There are various ways in most programming languages to accomplish all of the functionality of regular expressions. Sometimes it is easier to use a programming environment's resources to accomplish a text manipulation task. However, when the task becomes complicated, regular expressions generally provide a system of specifying what it is that you want that is actually much simpler and more specific than programming approaches.

Programming approaches are also highly variable. One might use a "substring" command 10 different ways in 10 different languages while a regular expression maintains very good consistency in many different environments. Regular expressions are a key feature of Perl, Python, TCL, and other scripting languages. In other languages such as C/C++, Java, and most others, regular expressions are optional yet common features and can often be the best way to solve problems.