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

Substitution

Processing...

Code Generator

Language

Generated Code

use strict; my $str = '10-10-2017 10-10-2017 10-10-2017 10-1-2018 10-1-2018 10-1-2018 10-1-2018 10-1-2018 10-1-2018 10-2-2018 10-2-2018 10-2-2018 10-3-2018 10-3-2018 10-7-2017 10-7-2017 10-7-2017 10-7-2017 10-7-2017 10-7-2017 10-7-2017 10-8-2017 10-8-2017 10-8-2017 10-8-2017 10-9-2017 10-9-2017 1-10-2017 1-10-2017 1-10-2017 1-10-2017 11-10-2017 11-10-2017 11-11-2017 11-11-2017 11-11-2017 11-11-2017 1-112017 1-11-2017 1-11-2017 1-11-2017 1-11-2017 1-11-2017 11-1-2018 11-1-2018 11-1-2018 11-1-2018 1-1-2017 1-1-2018 1-1-2018 1-1-2018 11-2-2018 11-2-2018 11-2-2018 11-7-2017 12-11-2017 1-2-2018 1-2-2018 1-2-2018 1-2-2018 12-2-2018 12-2-2018 12-2-2018 12-2-2018 12-2-2018 12-2-2018 12-3-2018 12-3-2018 12-3-2018 12-3-2018 12-3-2018 12-3-2018 12-3-2018 12-7-2017 12-7-2017 12-7-2017 12-7-2017 12-7-2017 12-7-2017 12-7-2017 12-9-2017 13-11-2017 13-11-2017 13-11-2017 13-1-2018 13-1-2018 13-1-2018 1-3-2018 1-3-2018 13-6-2017 13-7-2017 13-7-2017 13-7-2017 13-7-2017 13-7-2017 13-7-2017 13-7-2017 13-8-2017 13-8-2017 13-8-2017 13-8-2017 13-8-2017 13-9-2017 13-9-2017 13-9-2017 14-10-2017 14-10-2017 14-10-2017 14-11-2017 14-11-2017 14-11-2017 14-1-2018 14-1-2018 1-4-2018 1-4-2018 1-4-2018 14-2-2018 14-3-2018 14-3-2018 14-3-2018 14-3-2018 14-3-2018 14-3-2018 14-7-2017 14-8-2017 14-8-2017 14-8-2017 15-10-2017 15-10-2017 15-11-2017 15-11-2017 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-1-2018 15-2-2018 15-2-2018 15-2-2018 15-2-2018 15-3-2018 15-3-2018 15-7-2017 15-7-2017 15-7-2017 15-7-2017 15-7-2017 16-10-2017 16-10-2017 16-10-2017 16-10-2017 16-11-2017 16-11-2017 16-11-2017 16-11-2017 16-1-2018 16-7-2017 16-7-2017 16-7-2017 16-8-2017 16-8-2017 16-9-2017 16-9-2017 16-9-2017 16-9-2017 16-9-2017 17-10-2017 17-10-2017 17-10-2017 17-11-2017 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-1-2018 17-2-2018 17-2-2018 17-2-2018 17-3-2018 17-3-2018 17-3-2018 17-7-2017 17-7-2017 17-7-2017 17-7-2017 17-7-2017 17-7-2017 17-9-2017 17-9-2017 17-9-2017 18-10-2017 18-10-2017 18-10-2017 18-10-2017 18-10-2017 18-11-2017 18-11-2017 18-1-2018 18-1-2018 18-1-2018 18-1-2018 18-1-2018 1-8-2017 1-8-2017 1-8-2017 1-8-2017 18-2-2018 18-3-2018 18-3-2018 18-3-2018 18-7-2017 18-7-2017 18-7-2017 18-7-2017 18-7-2017 18-7-2017 18-9-2017 19-10-2017 19-10-2017 19-10-2017 19-10-2017 19-10-2017 19-11-2017 19-11-2017 19-2-2018 19-2-2018 19-2-2018 19-3-2018 19-3-2018 19-3-2018 19-3-2018 19-3-2018 19-3-2018 19-8-2017 19-8-2017 19-8-2017 19-8-2017 20-1-2018 20-1-2018 20-1-2018 20-1-2018 20-1-2018 20-1-2018 20-1-2018 '; my $regex = qr/(.*)(-)(.*)(-)(.*)/mp; my $subst = '\\5\\4\\3\\2\\1'; my $result = $str =~ s/$regex/$subst/rg; print "The result of the substitution is' $result\n";

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