Regular Expressions 101

Save & Share

  • Regex Version: ver. 1
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

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
No Match

/
/
g

Test String

Code Generator

Language

Generated Code

re = /<center>(.|\n)*?<\/center>/ str = '</head> <body style="background-color:#9b9b9b;"> **<center> <table width="580" border="0" cellspacing="0" cellpadding="0" align="center" class ="responsive-table" style="background-color:#3e5b3e;border:solid thin #3e5b3e;" > <tbody> <tr> <td background="http://app.randomsite.com/js/ckfinder/userfiles//images/banner.jpg" style="padding-top:20px;padding-right:20px;padding-left:20px;" class="hideForMobile"><h1 style="font-family:Arial, Helvetica, sans-serif;font-size:20px;font-weight:bold;text-align:right;color:#eee;vertical-align:bottom;text-decoration:none;margin-top:0;margin-bottom:0;margin-right:0;margin-left:0;" >some message</h1></td> </tr> <tr> </center>** <!---Start of Banner Image---> <td><a href="{{Custom1}}" style="color:inherit;text-decoration:none;" ><img src="http://app.clientcommand.com/js/ckfinder/userfiles//images/top-dollar-ford-banner.jpg" alt="" class="table.responsiveImage" style="display:block;width:100%;border-style:none;" /></a></td> <!---End of Banner Image---> </tr> <tr> **<center> <table width="580" border="0" cellspacing="0" cellpadding="0" align="center" class ="responsive-table" style="background-color:#3e5b3e;border:solid thin #3e5b3e;" > <tbody> <tr> <td background="http://app.randomsite.com/js/ckfinder/userfiles//images/banner.jpg" style="padding-top:20px;padding-right:20px;padding-left:20px;" class="hideForMobile"><h1 style="font-family:Arial, Helvetica, sans-serif;font-size:20px;font-weight:bold;text-align:right;color:#eee;vertical-align:bottom;text-decoration:none;margin-top:0;margin-bottom:0;margin-right:0;margin-left:0;" >some message</h1></td> </tr> <tr> </center>**' # Print the match result str.scan(re) do |match| puts match.to_s end

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 Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html