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

use strict; my $str = '2015-08-10 2015-10-08 12015-08-10 -2015-08-10 +2015-08-10 0015-08-10 1582-10-10 2015-02-28 2016-02-29 2000-02-29 0000-02-29 -2000-02-29 -2016-02-29 200000-02-29 2016-366 2000-366 0000-366 -2016-366 -2000-366 2015-081 2015-W33-1 2015-W53-7 2015-08-10 '; my $regex = qr/^[+-]?(\d{4,10}-((00[1-9]|0[1-9]\d|[12]\d\d|3[0-5]\d|36[0-5])|(0[1-9]|1[0-2])-(0[1-9]|1\d|2[0-8])|(0[13-9]|1[0-2])-(29|30)|(0[13578]|1[02])-31|W(0[1-9]|[1-4]\d|5[0-2])-[1-7]))|((\d{2,8}([13579][26]|[2468][048]|0[48])|(\d{0,6}([13579][26]|[02468][048])00))-(366|02-29))|(\+?\d{0,6}(([02468][048]|[13579][26])([26]0|71|[38]2|[49]3|[05]4|15|[27]6|37|[48]8|[09]9)|([02468][159]|[13579][37])(50|[16]1|[27]2|33|[48]4|[09]5|[15]6|67|[27]8|[38]9)|([02468][26]|[13579][048])([48]0|[09]1|[15]2|63|[27]4|[38]5|[49]6|[05]7|[16]8|29)|([02468][37]|[13579][159])([27]0|[38]1|[49]2|[05]3|[16]4|25|[37]6|87|[049]8|[5]9))|-\d{0,6}(([02468][048]|[13579][26])(0[28]|1[39]|24|3[06]|4[17]|5[28]|6[49]|75|8[06]|9[27])|([02468][159]|[13579][37])(0[49]|15|2[06]|3[27]|4[38]|54|6[05]|7[16]|8[28]|9[39])|([02468][26]|[13579][048])(0[51]|16|2[28]|3[39]|44|5[06]|6[17]|7[28]|8[49]|95)|([02468][37]|[13579][159])(0[17]|1[28]|2[49]|35|4[06]|5[27]|6[38]|74|8[05]|9[16])))-W53-[1-7]$/mp; 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