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
No Match

/
/
gU

Test String

Code Generator

Language

Generated Code

$re = '/<article(?: class="lead")?><a href=".*" target="_top"><img(?: height=".*")? src="(.*)"(?: width=".*")? \/><\/a><h[1,2]><a href="(.*)" target="_top">(.*)<\/a><\/h[1,2]><small>By .*<\/small><small>Updated: (.*) - (.*)<\/small><div class="clear"><\/div><\/article>/U'; $str = '<section class="news"><article class="lead"><a href="/2016/04/15/what-are-the-10-most-intriguing-games-of-the-2016-nfl-season/a6ikhoo/" target="_top"><img src="/_internal/cimg!0/8p7xcgnjxaoqjj4iwxfv1qlid4ag0mm" /></a><h1><a href="/2016/04/15/what-are-the-10-most-intriguing-games-of-the-2016-nfl-season/a6ikhoo/" target="_top">What are the 10 most intriguing games of the 2016 NFL season?</a></h1><small>By NATE ATKINS and ARTHUR ARKUSH</small><small>Updated: April 15, 2016 - 9:08 am</small><div class="clear"></div></article><div class="clear"></div></section><div class="bigbox ad"></div><section class="news secondary"><article><a href="/2016/04/08/green-bay-packers-cut-ilb-nate-palmer-10-game-starter-in-2015/afybdi5/" target="_top"><img height="225" src="/_internal/cimg!0/pes2uiv39y78ld1yezq38oqcz3invi8" width="400" /></a><h2><a href="/2016/04/08/green-bay-packers-cut-ilb-nate-palmer-10-game-starter-in-2015/afybdi5/" target="_top">Green Bay Packers cut ILB Nate Palmer, 10-game starter in 2015</a></h2><small>By ARTHUR ARKUSH -- aarkush@profootballweekly.com</small><small>Updated: April 8, 2016 - 4:01 pm</small><div class="clear"></div></article><article><a href="/2016/04/08/jacksonville-jaguars-aaron-colvin-and-green-bay-packers-demetri-goodson-suspended-4-games-each-for-peds/ahkwuh8/" target="_top"><img height="225" src="/_internal/cimg!0/5jn3lvqyt16zr6tg7yqrhsavrr3eh45" width="400" /></a><h2><a href="/2016/04/08/jacksonville-jaguars-aaron-colvin-and-green-bay-packers-demetri-goodson-suspended-4-games-each-for-peds/ahkwuh8/" target="_top">Jacksonville Jaguars\' Aaron Colvin and Green Bay Packers\' Demetri Goodson suspended 4 games each for PEDs</a></h2><small>By ARTHUR ARKUSH -- aarkush@profootballweekly.com</small><small>Updated: April 8, 2016 - 3:23 pm</small><div class="clear"></div></article></section>'; preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0); // Print the entire match result var_dump($matches);

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 PHP, please visit: http://php.net/manual/en/ref.pcre.php