Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression

/
/
g

Test String

Code Generator

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"(((1[0-9]{2})|(2[0-5]{2})|[0-9]{1,2})\.){3}(((1[0-9]{2})|(2[0-5]{2})|[0-9]{1,2})):(\d{5})"; string input = @"<!DOCTYPE html PUBLIC ""-//W3C//DTD XHTML 1.0 Transitional//EN"" ""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd""> <html xmlns=""http://www.w3.org/1999/xhtml"" xml:lang=""en"" lang=""en""> <head> <meta http-equiv=""Content-Type"" content=""text/html; charset=utf-8"" /> <meta name=""title"" content=""eBot :: Your ingame bot manager for CS:GO"" /> <title>eBot :: Your ingame bot manager for CS:GO</title> <link rel=""shortcut icon"" type=""image/png"" href=""/favicon.png"" /> <link rel=""stylesheet"" type=""text/css"" media=""screen"" href=""/css/bootstrap.min.css"" /> <link rel=""stylesheet"" type=""text/css"" media=""screen"" href=""/css/bootstrap-responsive.min.css"" /> <link rel=""stylesheet"" type=""text/css"" media=""screen"" href=""/css/tipsy.css"" /> <link rel=""stylesheet"" type=""text/css"" media=""screen"" href=""/css/datatable.bootstrap.css"" /> <link rel=""stylesheet"" type=""text/css"" media=""screen"" href=""/css/flags.css"" /> <link rel=""stylesheet"" type=""text/css"" media=""screen"" href=""/css/hubinfo.min.css"" /> <script type=""text/javascript"" src=""/js/jquery-1.8.2.min.js""></script> <script type=""text/javascript"" src=""/js/bootstrap.min.js""></script> <script type=""text/javascript"" src=""/js/jquery.validate.min.js""></script> <script type=""text/javascript"" src=""/js/jquery.tipsy.js""></script> <script type=""text/javascript"" src=""/js/jquery.tablesorter.min.js""></script> <script type=""text/javascript"" src=""/js/jquery.datatable.min.js""></script> <script type=""text/javascript"" src=""/js/datatable.bootstrap.js""></script> <script type=""text/javascript"" src=""/js/heatmap.js""></script> <script type=""text/javascript"" src=""/js/raphael-min.js""></script> <script type=""text/javascript"" src=""/js/jquery.iphone-switch.js""></script> <script type=""text/javascript"" src=""/js/hubinfo.min.js""></script> <script type=""text/javascript"" src=""/js/pnotify.custom.min.js""></script> <script type=""text/javascript"" src=""/js/aes.js""></script> <style type=""text/css""> body { padding-top: 60px; padding-bottom: 40px; } .sidebar-nav { padding: 9px 0; } </style> <!-- Le HTML5 shim, for IE6-8 support of HTML5 elements --> <!--[if lt IE 9]> <script src=""http://html5shim.googlecode.com/svn/trunk/html5.js""></script> <![endif]--> </head> <body> <script> function submitForm(id) { $(""#"" + id).submit(); } var socketIoAddress = ""176.31.211.228:12370""; var socket = null; var socketIoLoaded = false; var loadingSocketIo = false; var callbacks = new Array(); function initSocketIo(callback) { callbacks.push(callback); if (loadingSocketIo) { return; } if (socketIoLoaded) { if (typeof callback == ""function"") { callback(socket); } return; } loadingSocketIo = true; $.getScript(""http://""+socketIoAddress+""/socket.io/socket.io.js"", function(){ socket = io.connect(""http://""+socketIoAddress); socket.on('connect', function(){ socketIoLoaded = true; loadingSocketIo = false; if (typeof callback == ""function"") { callback(socket); } for (var c in callbacks) { callbacks[c](socket); } //callbacks = new Array(); }); }); } </script> <div class=""navbar navbar-inverse navbar-fixed-top""> <div class=""navbar-inner""> <div class=""container-fluid""> <a class=""btn btn-navbar"" data-toggle=""collapse"" data-target="".nav-collapse""> <span class=""icon-bar""></span> <span class=""icon-bar""></span> <span class=""icon-bar""></span> </a> <a class=""brand"" href=""/"">eBot-CSGO</a> <div class=""nav-collapse collapse""> <div style=""line-height: 35px; float: right; margin-right: 10px;""> <form style=""display:inline; margin-left: 5px; cursor: pointer"" action=""/switch/lang/fr"" method=""POST"" id=""langFr""><input type=""hidden"" name=""referer"" value=""/servers"" /><img onclick=""javascript:submitForm('langFr')"" src=""/images/fr.png"" /></form> <form style=""display:inline; margin-left: 5px; cursor: pointer"" action=""/switch/lang/en"" method=""POST"" id=""langEn""><input type=""hidden"" name=""referer"" value=""/servers"" /><img onclick=""javascript:submitForm('langEn')"" src=""/images/en.png"" /></form> <form style=""display:inline; margin-left: 5px; cursor: pointer"" action=""/switch/lang/de"" method=""POST"" id=""langDe""><input type=""hidden"" name=""referer"" value=""/servers"" /><img onclick=""javascript:submitForm('langDe')"" src=""/images/de.png"" /></form> <form style=""display:inline; margin-left: 5px; cursor: pointer"" action=""/switch/lang/cn"" method=""POST"" id=""langCn""><input type=""hidden"" name=""referer"" value=""/servers"" /><img onclick=""javascript:submitForm('langCn')"" src=""/images/cn.gif"" /></form> </div> <p class=""navbar-text pull-right""> Logged in as <a href=""#"" class=""navbar-link"">tictax</a> </p> <ul class=""nav""> <li class=""active""><a href=""/"">Home</a></li> <li><a href=""http://www.esport-tools.net/ebot"">Help</a></li> <li><a href=""http://www.esport-tools.net/about"">About</a></li> </ul> </div> </div> </div> </div> <div class=""container-fluid""> <div class=""row-fluid""> <div class=""span2""> <div class=""well sidebar-nav""> <script> function goToMatch() { var id = $(""#match_id_go"").val(); if (id > 0) document.location.href = ""/matchs/view/""+id; }; </script> <ul class=""nav nav-list""> <li class=""nav-header"">Main Menu</li> <li ><a href=""/"">Home</a></li> <li ><a href=""/stats"">Statistics</a></li> <li ><a href=""/credits"">Credits</a></li> <!--<li ><a href=""/main/ingame"">Ingame Help</a></li>--> <li class=""nav-header"">Match Menu</li> <li ><a href=""/matchs/current/1"">Matches in Progress <span class=""badge badge-info"">39</span></a></li> <li ><a href=""/matchs/archived/1"">Archived Matches</a></li> <li ><a href=""/seasons"">Seasons Overview</a></li> <li class=""nav-header"">Match Management</li> <li ><a href=""/matchs/create"">Create a match</a></li> <li ><a href=""/matchs/user"">My matchs <span class=""badge badge-info"">0</span></a></li> <li class=""nav-header"">Team Management</li> <li><a href=""/teams/create"">Create Team</a></li> <li><a href=""/teams"">Team Management</a></li> <li class=""nav-header"">Server Management</li> <li ><a href=""/servers/create"">Add Gameserver</a></li> <li><a href=""/servers"">Server Management</a></li> <li class=""nav-header"">Statistics</li> <li ><a href=""/stats/global"">Global Statistics</a></li> <li ><a href=""/stats/maps"">Statistics by Map</a></li> <li ><a href=""/stats/weapons"">Statistics by Weapon</a></li> </ul> </div> </div> <div class=""span10""> <h3>Server Management (1/2)</h3> <hr/> <table class=""table table-striped""> <thead> <tr> <th>#ID</th> <th>IP Adress</th> <th>Name</th> <th>used?</th> <th>Action</th> </tr> </thead> <tbody> <tr> <td width=""30"">3243</td> <td width=""200"">85.14.230.26:27015</td> <td>Xylonm Gameserver</td> <td width=""100""> <img src=""/images/icons/flag_red.png"" /> not used </td> <td width=""100""> <a href=""/servers/delete/3243""><button class=""btn btn-danger"">Delete</button></a> </td> </tr> </tbody> </table> </div> </div> <!-- Please, don't remove the brand --> <footer class=""footer""> <p>&copy; <a target=""_blank"" href=""http://www.esport-tools.net/ebot"">eSport-tools</a> 2012-2013 - 3.1.0 Public - By deStrO &amp; Basert - Follow me on <a target=""_blank"" href=""https://twitter.com/deStrO_BE"">Twitter</a> - Propulsed by <a target=""_blank"" href=""http://twitter.github.com/bootstrap"">Bootstrap</a> & <a target=""_blank"" href=""http://www.symfony-project.com"">Symfony</a> - Follow eBot on <a target=""_blank"" href=""https://github.com/deStrO/eBot-CSGO"">GitHub</a></p> </footer> <form action=""https://www.paypal.com/cgi-bin/webscr"" method=""post"" target=""_top""> <input type=""hidden"" name=""cmd"" value=""_donations""> <input type=""hidden"" name=""business"" value=""destro@esport-tools.net""> <input type=""hidden"" name=""lc"" value=""BE""> <input type=""hidden"" name=""item_name"" value=""eSport-tools.net""> <input type=""hidden"" name=""no_note"" value=""0""> <input type=""hidden"" name=""currency_code"" value=""EUR""> <input type=""hidden"" name=""bn"" value=""PP-DonationsBF:btn_donateCC_LG.gif:NonHostedGuest""> <input type=""image"" src=""https://www.paypalobjects.com/en_US/BE/i/btn/btn_donateCC_LG.gif"" border=""0"" name=""submit"" alt=""PayPal - The safer, easier way to pay online!""> <img alt="" border=""0"" src=""https://www.paypalobjects.com/fr_XC/i/scr/pixel.gif"" width=""1"" height=""1""> </form> </div> <script type=""text/javascript""> var _gaq = _gaq || []; _gaq.push(['_setAccount', 'UA-22008669-4']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); </script> </body> </html> "; foreach (Match m in Regex.Matches(input, pattern)) { Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index); } } }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx