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

/
/

Test String

Code Generator

Language

Generated Code

use strict; my $str = 'STAT 545 REGULAR EXPRESSION TEST BED ------------------------------------ abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLMNOPQRSTUVWXYZ 0123456789 +-.,!@#$%^&*();\\/|<>"\' 12345 -98.7 3.141 .6180 9,000 +42 Twas brillig, and the slithy toves Did gyre and gimble in the wabe; All mimsy were the borogoves, And the mome raths outgrabe. 3317 Route 202 Long Branch, NJ 07740 9303 Route 1 Sun City, AZ 85351 CHALLENGES ------------------------------------- RULES 1. Match ONLY the target elements (check top of document as well!) 2. Must be a separate match for each discrete element 3. THERE ARE CANDY PRIZES 1. DNA: TCCGTATCAAGATCCTCTTAATAAGCCCCCGTCACTGTTGGTTGTAGAGCCCAGGACGGGTTGGCCAGATGTGCGACTATATCGCTTAGTGGCTCTTGGGCC GATAGCTTCTTACCGGTGCGCCTCCGTACGCAGTACGATCGCACGCCCCATGAGAACGATAGGTAAACCTGGTGTCCTGTGAGCGACAAAAGCTTAAATGG 2. SMILIES: :D :) :o :P :/ 3. EMAIL ADDRESSES: foo@demo.net bar.ba@test.co.uk 4. HTML Tags: <p>The <a class="APILink" target="_blank" href="https://docs.oracle.com/javase/8/docs/api/java/util/regex/Pattern.html"><code>Pattern</code></a> API contains a number of useful <i>predefined character classes</i>, which offer convenient shorthands for commonly used regular expressions:</p> <p><a name="CHART" id="CHART"></a></p> 5. PHONE NUMBERS: 555.123.4567 +1-800-555-2468 +49 7743 9901 6. URLs: www.demo.com http://foo.co.uk/ 7. MACHO MAN RANDY SAVAGE QUOTATIONS: “History beckons the Nacho Man.” “Hulkamania is like a single grain of sand in the Sahara desert that is Nacho Madness.” "Snap into a Slim Jim!" 9. CITATIONS: We based our calculations on previously published methods (Nadeu 2006). We also used a support vector machine, which is a classification method that is able to deal with highly variable data (Camps-Valls et al. 2004). The population of this species...where the presence and transmission of introduced avian malaria (Plasmodium relictum) is low (Eggert et al. 2008, Dziel et al. 2010)'; my $regex = qr/a/p; if ( $str =~ /$regex/ ) { 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