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

/
/
g

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

use strict; my $str = 'define(function(require, exports, module) { var UIKit = require(\'uikit/uikit\'); var ExtendUtil = require(\'helpers/extend.util\'); var ConfirmModalView = UIKit.Modal2.extend({ define([ \'underscore\', \'marionette\', \'../libs/spf.helper\', \'../templates\', \'uikit/injector\', \'uikit/component.collection.view\', \'uikit/grid\', \'uikit/table\', \'uikit/text\', \'uikit/button\' ], function(_, Mn, // data stuff SPFHelper, Templates, // view stuff InjectorView, ComponentCollectionView, GridView, TableView, TextView, ButtonView) {'; my $regex = qr/(define[\s\S]*{)([\s\S\n\r]+?)(var\s+)([$\w_]+)(\s+)(.*)([,;])([\s\S\n\r]+?)(\w)/p; my $subst = '\\1\\2var _ = require(\'underscore\'),\\8 \\4\\5\\6\\7\\8\\9'; 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