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

/
/
gm

Test String

Code Generator

Language

Generated Code

use strict; my $str = '11—04—2022 ACH Deposit Square Inc 221104P2 126.42 11—07—2022 ACH Deposit Square Inc 221107P2 184.86 11—07—2022 ACH Deposit Square Inc 221107P2 225.67 11—09—2022 ACH Deposit Square Inc 221109P2 277.19 11—10—2022 ACH Deposit Square Inc 221110P2 306.31 11—14—2022 ACH Deposit Square Inc 221114P2 19.38 11—14—2022 ACH Deposit Square Inc 221111P2 126.42 11—14—2022 ACH Deposit Square Inc 221114P2 213.98 11—16—2022 ACH Deposit Square Inc 221116P2 175.02 11—17—2022 ACH Deposit Square Inc 221117P2 157.49 11—18—2022 ACH Deposit Square Inc 221118P2 308.4'; my $regex = qr/0?(?P<month>10|11|12|1|2|3|4|5|6|7|8|9)[—](?P<day>[1-2][0-9]|3[0-1]|[0]?[1-9])[—](?P<year>(19|20)\d{2})[ ](?P<desc>.*?)[ ](?P<amount>[-]?[S]?\d*\.\d+)/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