Regular Expressions 101

Save & Share

  • Regex Version: ver. 3
  • 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

/
/
gi

Test String

Code Generator

Language

Generated Code

use strict; my $str = '<div> <p>foo</p> <script type=\'text/javascript\'>another script goes here</script> </div> <script type=\'text/javascript\'> var googletag = googletag || {}; googletag.cmd = googletag.cmd || []; (function() { var gads = document.createElement(\'script\'); gads.async = true; gads.type = \'text/javascript\'; var useSSL = \'https:\' == document.location.protocol; gads.src = (useSSL ? \'https:\' : \'http:\') + \'//www.googletagservices.com/tag/js/gpt.js\'; var node = document.getElementsByTagName(\'script\')[0]; node.parentNode.insertBefore(gads, node); })(); </script> <div> <p>bar</p> <script type=\'text/javascript\'>yet another script goes here</script> </div> <script type=\'text/javascript\'> googletag.cmd.push(function() { googletag.defineSlot(\'/6176201/Opera_120x600\', [120, 600], \'div-gpt-ad-6176201-opera_120x600\').addService(googletag.pubads()); googletag.defineSlot(\'/6176201/Opera_300x250\', [300, 250], \'div-gpt-ad-6176201-opera_300x250\').addService(googletag.pubads()); googletag.defineSlot(\'/6176201/Opera_728x90\', [728, 90], \'div-gpt-ad-6176201-opera_728x90\').addService(googletag.pubads()); googletag.defineSlot(\'/6176201/Contextuals_Operaweb\', [557, 30], \'div-gpt-ad-6176201-contextuals_operaweb\').addService(googletag.pubads()); googletag.pubads().collapseEmptyDivs(); googletag.pubads().enableSingleRequest(); googletag.enableServices(); }); </script> <script type=\'text/javascript\'> googletag.cmd.push(function() { googletag.display(\'div-gpt-ad-6176201-opera_728x90\'); }); </script> <div></div><script type=\'text/javascript\'>this script must stay too</script><a></a> <script type=\'text/javascript\'> googletag.cmd.push(function() { googletag.display(\'div-gpt-ad-6176201-opera_120x600\'); }); </script>'; my $regex = qr/<script type='text\/javascript'(?:(?!<\/?script).\n)+?(\n*.*?)*?(googletag)(\n*.*?)*(?:(?!<\/?script>))*?<\/script>/ip; if ( $str =~ /$regex/g ) { print "Whole match is ${^MATCH} and its start/end positions can be obtained via \$-[0] and \$+[0]\n"; # print "Capture Group 1 is $1 and its start/end positions can be obtained via \$-[1] and \$+[1]\n"; # print "Capture Group 2 is $2 ... and so on\n"; } # ${^POSTMATCH} and ${^PREMATCH} are also available with the use of '/p' # Named capture groups can be called via $+{name}

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 Perl, please visit: http://perldoc.perl.org/perlre.html