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

const regex = /TR\$.+?(?=\n)/; // Alternative syntax using RegExp constructor // const regex = new RegExp('TR\\$.+?(?=\\n)', '') const str = `TR\$1b3abc T0b0 4 0 20151117 062231 7 14 15 c0a81e03 0 0 1 00A 3 481915101 3 481915101 0 1 3 90047975097350 001 0 3 975097350 1 9 F10 XT 131550-251897 FT110393_RT43 loop[gw_sip,PR970149981] 0 D00c 3108 222e42 E007 020103 H018 3 481915101 10 TRAFTERM G033 20151117 06223185 0000000050 0000000772 0000001484 V013 0 20 0 0 0 SIP_OUT O038 7109 58056 56252 354 343 0 4 0 IP2TDM 192.168.31.6:6372 Z02c 20925-DY-0001b6a8-523106f36@sip.mystream.fr GO\$18c T0a3 185 0 20151117 063030 6 17 18 c0a81e03 1 0 1 00A 3 139947700 3 139947752 0 1 3 629452310 001 0 3 629452310 1 24 B10 XT 265720-251900 SIP loop[gw_sip,PEER_SFR_2] 0 D00c 3108 222e48 G033 20151117 06303070 0000000071 0000001140 0000001731 L008 1 1 3 1 E007 020103 Y005 3 15 V012 8 20 0 0 0 SIP_IN V013 8 20 0 0 0 SIP_OUT Z02c 21325-EZ-0001b7ed-3b997c5d2@sip.mystream.fr Z00d 70b7375a@pbx`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; if ((m = regex.exec(str)) !== null) { // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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 JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions