Regular Expressions 101

Save & Manage Regex

  • Current Version: 1
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
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
Processing...

Test String

Substitution
Processing...

Code Generator

Language

Generated Code

$re = '/(^\s+|\s*?(\r?\n)\s*|\s+$)/'; $str = ' 2002 Why Orwell Matters, Basic Books (US)/UK edition as Orwell\'s Victory, Allen Lane/The Penguin Press. 2005 Thomas Jefferson: Author of America. Eminent Lives/Atlas Books/HarperCollins Publishers, ISBN 0-06-059896-4 2006 Thomas Paine\'s "Rights of Man": A Biography. Books That Shook the World/Atlantic Books, ISBN 1-84354-513-6 2007 God Is Not Great: How Religion Poisons Everything. Twelve/Hachette Book Group USA/Warner Books, ISBN 0-446-57980-7 / Published in the UK as God Is Not Great: The Case Against Religion. Atlantic Books, ISBN 978-1-84354-586-6 2007 The Portable Atheist: Essential Readings for the Non-Believer. Perseus Publishing. ISBN 978-0-306-81608-6 (editor) 2010 Hitch-22 Some Confessions and Contradictions: A Memoir . Hachette Book Group. ISBN 978-0-446-54033-9 (published by Allen and Unwin in Australia in May 2010 with the shorter title: Hitch-22. A Memoir.) ISBN 978-1-74175-962-4 2012 Mortality. Atlantic. Pamphlets 1971 Karl Marx and The Paris Commune. Sidgwick & Jackson Ltd. ISBN 0283484829 1990 The Monarchy: A Critique of Britain\'s Favourite Fetish. Chatto & Windus, 1990. 1995 The Missionary Position: Mother Teresa in Theory and Practice. Verso. 2003 A Long Short War: The Postponed Liberation of Iraq. Plume Books. Originally released as Regime Change (Penguin). 2011 The '; $subst = "\2"; $result = preg_replace($re, $subst, $str); echo "The result of the substitution is ".$result;

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