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 single character of: a, b, c or d
    [[ab][cd]]
  • 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]
  • Character class intersection
    [\w&&[^\d]]
  • 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 = 'import { Metadata } from \'next\'; import CreateEnactment from \'./_components\'; import { translationServer } from \'i18n\'; import { hasPermissionServerSide } from \'utils\'; const CreateEnactmentPage = async () => { await hasPermissionServerSide({ branchRoles: [\'ADMIN\', \'OPERATOR\'] }); return <CreateEnactment />; }; export async function generateMetadata({ params: { locale, enactmentId } }: { params: Params }): Promise<Metadata> { const { t } = await translationServer(locale, \'projectTitles\'); const translate = enactmentId === \'new-enactment\' ? t(\'newEnactment\') : t(\'viewEnactment\'); // to meta tag return { title: translate }; } export default CreateEnactmentPage; '; my $regex = qr/export\s+async\s+function\s+generateMetadata\s*\(\s*\{[\s\S]*?\}\s*\):\s*Promise<Metadata>\s*{\s*const\s*\{\s*t\s*\}\s*=\s*await\s*translationServer\s*\(\s*locale\s*,\s*'projectTitles'\s*\);\s*return\s*\{\s*title\s*:\s*translate\s*\}?\s*}/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