Regular Expressions 101

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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

/
/
gm

Test String

Code Generator

Language

Generated Code

$re = '/(?<=parsable-cite=\\\\\")\w{2}\/\d{3}\/\d{3}/m'; $str = '{"billnumber": "499", "billbody": "<bill bill-stage=\\"Introduced-in-Senate\\" public-private=\\"public\\">\\n <metadata xmlns:dc=\\"http://purl.org/dc/elements/1.1/\\">\\n <dublinCore>\\n <dc:title>113 S499 IS: Patient Choice Restoration Act</dc:title>\\n <dc:publisher>U.S. Senate</dc:publisher>\\n <dc:date>2013-03-07</dc:date>\\n <dc:format>text/xml</dc:format>\\n <dc:language>EN</dc:language>\\n <dc:rights>Pursuant to Title 17 Section 105 of the United States Code, this file is not subject to copyright protection and is in the public domain.</dc:rights>\\n </dublinCore>\\n </metadata>\\n <form>\\n <distribution-code display=\\"yes\\">II</distribution-code>\\n <congress>113th CONGRESS</congress>\\n <session>1st Session</session>\\n <legis-num>S. 499</legis-num>\\n <current-chamber>IN THE SENATE OF THE UNITED STATES</current-chamber>\\n <action>\\n <action-date date=\\"20130307\\">March 7, 2013</action-date>\\n <action-desc>\\n <sponsor name-id=\\"S299\\">Mr. Vitter</sponsor>(for himself\\n\\t\\t\\t and<cosponsor name-id=\\"S355\\">Mr. Cruz</cosponsor>) introduced the following\\n\\t\\t\\t bill; which was read twice and referred to the<committee-name committee-id=\\"SSFI00\\">Committee on\\n\\t\\t\\t Finance</committee-name>\\n </action-desc>\\n </action>\\n <legis-type>A BILL</legis-type>\\n <official-title>To repeal the Patient Protection and Affordable Care\\n\\t\\t Act.</official-title>\\n </form>\\n <legis-body>\\n <section id=\\"id6D79D62AF466494398FF5FE90F4B4C54\\" section-type=\\"section-one\\">\\n <enum>1.</enum>\\n <header>Short title</header>\\n <text display-inline=\\"no-display-inline\\">This Act may be cited as the<quote>\\n <short-title>Patient Choice Restoration\\n\\t\\t\\t Act</short-title>\\n </quote>.</text>\\n </section>\\n <section id=\\"idCD2A3EA9F06D44988B7B6592EC5A1643\\" section-type=\\"subsequent-section\\">\\n <enum>2.</enum>\\n <header>Repeal</header>\\n <subsection id=\\"idCEB3A1D87FE64817A5F57C139C2503BA\\">\\n <enum>(a)</enum>\\n <header>In\\n\\t\\t\\t general</header>\\n <text display-inline=\\"yes-display-inline\\">The following Acts,\\n\\t\\t\\t and the amendments made by such Acts, are repealed:</text>\\n <paragraph id=\\"idF23F83A55FFE4D6BBDD8E6A089D8E9A5\\">\\n <enum>(1)</enum>\\n <text display-inline=\\"yes-display-inline\\">The<cato:entity xmlns:cato=\\"http://namespaces.cato.org/catoxml\\" entity-type=\\"law-citation\\">\\n <cato:entity-ref entity-type=\\"act\\" value=\\"Patient Protection and Affordable Care Act\\">Patient Protection and Affordable Care\\n\\t\\t\\t Act</cato:entity-ref>(<external-xref legal-doc=\\"public-law\\" parsable-cite=\\"pl/111/148\\">Public Law 111\\u2013148</external-xref>)</cato:entity>.</text>\\n </paragraph>\\n <paragraph id=\\"id2BD61EF1ED3E451182DDEDD02FFC6850\\">\\n <enum>(2)</enum>\\n <text display-inline=\\"yes-display-inline\\">The<cato:entity xmlns:cato=\\"http://namespaces.cato.org/catoxml\\" entity-type=\\"law-citation\\">\\n <cato:entity-ref entity-type=\\"act\\" value=\\"Health Care and Education Reconciliation Act of 2010\\">Health Care and Education\\n\\t\\t\\t Reconciliation Act of 2010</cato:entity-ref>(<external-xref legal-doc=\\"public-law\\" parsable-cite=\\"pl/111/152\\">Public Law 111\\u2013152</external-xref>)</cato:entity>.</text>\\n </paragraph>\\n </subsection>\\n <subsection id=\\"idE7C3196B19BF4FBC9B58ED08B87DBAC3\\">\\n <enum>(b)</enum>\\n <header>Effect of\\n\\t\\t\\t law</header>\\n <text>The provisions of law amended by the Acts referred to in<cato:entity-ref xmlns:cato=\\"http://namespaces.cato.org/catoxml\\" entity-type=\\"act\\" value=\\"Patient Choice Restoration Act/s:2/ss:a\\" proposed=\\"true\\">subsection (a)</cato:entity-ref>are restored as if such Acts had never been enacted.</text>\\n </subsection>\\n </section>\\n </legis-body>\\n</bill>", "billversion": "is", "congress": "113", "billtype": "s"}'; 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