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 = '# Table | Syntax test | Description | Test | XXX | XXX | | ----------- | ----------- | ---- | --- | --- | | Header | Title | AAAA | XXX | XXX | | Header | Title | AAAA | XXX | XXX | | Paragraph | Text | BBBB | XXX | XXX | ## Pretty table |Header 1|Header 2| |---|---| |![Kitty](https://placekitten.com/200/300 "Kitten")|![Kitty](https://placekitten.com/200/300? "Kitten")| ### Lists --- - Inline *code* `aaaaz` - My **favorite search** engine is ~~not~~ [Duck Duck Go](https://duckduckgo.com "Click me"). - ~~***Recursive***~~ - ***~~Recursive reversed~~*** - Item 4 1. Item 2. Item 3. Item 4. Item 1. c 1. c #### Multiline code ``` int method() { return 2137; } ``` ##### Quotes > aa > aa > > bb > > bb > > > [c](#panes)c > > > cc > > bb > > bb > aa > aa > single line '; my $regex = qr/(^\|(?<tableSeparator>[\s\-|]+)\|\n)|(^\|\s*(?<tableTopFirst>[^|]+)(?=.*\n\|\s*-))|((?<!^)\|(?<tableTopMiddle>[^|\n]+)(?=\|.*\|\n\| -))|(\|(?<tableTopLast>[^|]+)\|\n(?=\|\s*-))|(^\|\s*(?<tableBottomFirst>[^|]+)(?=.*\n^[^|]))|((?<!^)\|(?<tableBottomMiddle>[^|\n]+)(?=\|.*\|\n[^|]))|(\|\s*(?<tableBottomLast>[^|]+)\|\n(?!\|))|(^\|\s*(?<tableMiddleFirst>[^|]+)(?=\|))|(\|\s*(?<tableMiddleLast>[^|]+)\|\n)|(\|\s*(?<tableMiddleMiddle>[^|]+))|!?(\[(?<text>[^(]+)]\((?<url>[^")]+))("(?<title>[^"]+)"|.*)\)|((?<!-.+\n)- (?<unorderedListFirstItem>.+)\n)|((?<=-.+\n)- (?<unorderedListMiddleItem>.+)\n(?=-))|(- (?<unorderedListLastItem>.+)\n(?!-))|((?<!\d+\..+\n)\d+\. (?<orderedListFirstItem>.+)\n)|((?<=\d+\..+\n)\d+\. (?<orderedListMiddleItem>.+)\n(?=\d+\.))|(\d+\. (?<orderedListLastItem>.+)\n(?!\d+\.))|(\*\*\*(?<boldAndItalic>[^*]*)\*\*\*)|(\*\*(?<bold>[^*]*)\*\*)|(\*(?<italic>[^*]*)\*)|(~~(?<strikethrough>[^~]*)~~)|(`{3}\n(?<multilineCode>[^`]+)`{3}\n)|(`(?<inlineCode>[^`\n]*)`)|(^#{6} (?<h6>.+))|(^#{5} (?<h5>.+))|(^#{4} (?<h4>.+))|(^#{3} (?<h3>.+))|(^#{2} (?<h2>.+))|(^# (?<h1>.+))|(?<horizontalLine>^-{3}\n)|(?<=^\n)> (?<singleLineQuote>.+)\n(?!^>)|((?<!> .+\n)> (?<quoteFirst>.+))|(> (?<quoteLast>.+)(?!.*\n> .+))|(> (?<quoteMiddle>.+))|(?<lineBreak>\n{2})/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