using System.Text.RegularExpressions;

Imports System.Text.RegularExpressions

For JavaScript code running in a browser:

<script src="xregexp-all-min.js"></script>

For JavaScript code running on a server using Node.js:

var XRegExp = require('xregexp').XRegExp;

import java.util.regex.*;

import re

If you place the using statement at the top of your C# source file, you can reference the classes that provide regular expression functionality directly, without having to fully qualify them. For instance, you can write Regex() instead of System.Text.RegularExpressions.Regex().

If you place the Imports statement at the top of your VB.NET source file, you can reference the classes that provide regular expression functionality directly, without having to fully qualify them. For instance, you can write Regex() instead of System.Text.RegularExpressions.Regex().

You have to import the java.util.regex package into your application to be able to use Java’s built-in regular expression library.

JavaScript’s regular expression support is built-in and always available.

If you want to use XRegExp to extend JavaScript’s regular expression syntax, your web page will need to load the XRegExp library. The easiest way to do that is to load xregexp-all-min.js which includes all of XRegExp’s functionality in minimized form. The XRegExp recipes in this book assume you’re doing just that.

If you’re concerned about page loading times and you do not use Unicode categories, blocks, and/or scripts, you can load the base library xregexp-min.js and load the addon libraries as needed. Load unicode-base.js to enable the ‹\p{⋯}› syntax for Unicode properties. You can then load unicode-blocks.js, unicode-categories.js, and/or unicode-scripts.js to make it possible to match Unicode blocks, categories, and/or scripts with ‹\p{⋯}›.

If you are using Node.js to run JavaScript on a server, then you’ll need to install XRegExp as an npm package. This can be done by entering npm install xregexp on the command line. Once installed, your server-side scripts can import the XRegExp library as shown in the Solution section.

The preg functions are built-in and always available in PHP 4.2.0 and later.

Perl’s regular expression support is built-in and always available.

You have to import the re module into your script to be able to use Python’s regular expression functions.

Ruby’s regular expression support is built-in and always available.