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

/
/

Test String

Code Generator

Generated Code

$re = '/((\d+) (C\.F\.R|U\.S\.C). (§) ((\d+\.?\d+)(\(\w+\))?(\(\d+\))?(\(\w+\))?( \w+ )(\(\w+\))?(;)))|(\d+) (U\.S\.C)\. (§) (\d+)(\W+)(\w+)(\W+)(\d+)(\W+)(\w+)(\W+)|((\d+) (C\.F\.R|U\.S\.C). (§) (\d+.\.?\d+))/'; $str = '" 5 C.F.R. § 2424.32(a) and (c); <i>AFGE, Local 1858</i>, 56 FLRA 1115, 1117 (2001). The Authority has held that a union\'s lack of response constituted a concession to an<final tooltip=\'CUE phrase-fact\'> <final tooltip=\'CUE phrase-fact\'> <final tooltip=\'CUE phrase-fact\'> <final tooltip=\'CUE phrase-fact\'>agency\'s argument</final> the proposal interferes with its management right to layoff employees under 5 U.S.C. § 7106(a)(2)(A). SOP at 11. The Agency<intial tooltip=\'CUE phrase-intial\'> <intial tooltip=\'CUE phrase-intial\'> <intial tooltip=\'CUE phrase-intial\'> <intial tooltip=\'CUE phrase-intial\'> affects management\'s right to layoff employees under § 7106(a)(2)(A) of the Statute, it is outside the<rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale 5 C.F.R. § 2424.32 tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'>duty to bargain</rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> . <i>Int\'l Ass\'n of Machinists &amp; Aerospace Workers</i>, 59 FLRA 830, 831 (2004); <i>Tidewater Va. Fed. Employees Metal Trades Council</i>, 58 FLRA 561, 563 (2003) (citing <i>NFFE, Local 1904</i>, 57 FLRA 28, 29 (2001)). In accordance with Authority precedent set forth above, Proposal 2 is outside the<rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'>duty to bargain</rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> . n2 <footnote fn-num="2">Given the above,<rationale tooltip=\'CUE phrase-fact\'>it is unnecessary to address the</rationale>Agency\'s argument that Proposal 2 concerns supervisors and therefore is only negotiable at the election of the Agency.</footnote><b>IX. Order</b> Proposal 1 is negotiable only at the election of the Agency and Proposal 2 is not<fact tooltip=\'CUE phrase-fact\'> <fact tooltip=\'CUE phrase-fact\'> <fact tooltip=\'CUE phrase-fact\'> <fact tooltip=\'CUE phrase-fact\'> <fact tooltip=\'CUE phrase-fact\'> <fact tooltip=\'CUE phrase-fact\'> <fact tooltip=\'CUE phrase-fact\'> <fact tooltip=\'CUE phrase-fact\'> <fact tooltip=\'CUE phrase-fact\'> <fact tooltip=\'CUE phrase-fact\'>within the<rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'> <rationale tooltip=\'CUE phrase-fact\'>duty to bargain</rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </rationale> </fact> </fact> </fact> </fact> </fact> </fact> </fact> </fact> </fact> </fact> , therefore, the petition with respect to Proposal 2<final tooltip=\'CUE phrase-fact\'>is dismissed</final> . </content><br>'; preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0); // Print the entire match result var_dump($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