Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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

/
/

Test String

Code Generator

Language

Generated Code

use strict; my $str = '</head> <body> <div id="kJAQ_" class="z-temp"><div id="zk_proc" class="z-loading"><div class="z-loading-indicator"><span class="z-loading-icon"></span>Processing...</div></div></div> <script class="z-runonce" type="text/javascript"> zkmx( [0,\'kJAQ_\',{dt:\'z_oec\',cu:\'/EfectoresWeb\',uu:\'/EfectoresWeb/zkau\',ru:\'/login.isp\'},[ [\'zul.utl.Style\',\'zk_comp_1\',{visible:false,src:\'/EfectoresWeb/css/PamiStyle.css\'},[]], [\'zul.wgt.Div\',\'zk_comp_2\',{id:\'div\',style:\'width:90%;margin:0 auto 0 auto;align:center\',prolog:\'\\n\\t\'},[ [\'zul.wgt.Include\',\'zk_comp_3\',{prolog:\'\\n\\t\\t\',_xcnt:\'<div id="kJAQ0" class="z-temp"><div id="zk_proc" class="z-loading"><div class="z-loading-indicator"><span class="z-loading-icon"></span>Processing...</div></div></div>\',_childjs:function(){zkmx( [0,\'kJAQ0\',{ow:\'zk_comp_3\'},[ [\'zul.wnd.Window\',\'zk_comp_38\',{id:\'winHeader\',$$onSize:false,$$onMaximize:false,$$onOpen:false,$$onMinimize:false,$$onZIndex:false,$onClose:true,$$onMove:false,prolog:\'\\n\\t\'},[ [\'zul.box.Box\',\'zk_comp_39\',{},[ [\'zul.box.Box\',\'zk_comp_40\',{id:\'hbox_header\',align:\'end\'},[ [\'zul.wgt.Image\',\'zk_comp_41\',{src:\'/EfectoresWeb/img/top.jpg\'},[]]],\'horizontal\']],\'vertical\']]]]]); }},[]], [\'zul.wnd.Window\',\'zk_comp_4\',{id:\'winLogin\',$onOK:true,$onClose:true,prolog:\'\\n\\t \\t\'},[ [\'zul.box.Box\',\'zk_comp_5\',{},[ [\'zul.box.Box\',\'zk_comp_6\',{id:\'hbox_menu\'},[],\'horizontal\'], [\'zul.wgt.Groupbox\',\'zk_comp_7\',{$$onOpen:false,width:\'890px\',closable:false},[ [\'zul.wgt.Caption\',\'zk_comp_8\',{id:\'caption_login\',sclass:\'z-title\',label:\'Login\'},[]], [\'zul.grid.Grid\',\'zk_comp_9\',{$$onRender:true,$'; my $regex = qr/^[\s\S]{0,30}/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