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 = /(\d{4}\x2f\d{2}\x2f\d{2}\s+\d{2}\x3a\d{2}\x3a\d{2})\x2e\d+\s+(\w+\x2b\d+\x3a\d+)\s+(\d{2}\x2e\d{3}\x2e\d{2}\x2e\d{3})\s+(\w{3}\s+\d+\s+\d{2}\x3a\d{2}\x3a\d{2})\s+(\w+\x2e\w+\x2e\w+\x2e\w+\x2e\w+)\s+(\d\x3b\d\x3b\w+\x2d\w+\x2d\w+\x2d\w+\x2d\w+)\x3b(\d+\x2d\d+\x2d\d+\x2d\d+\x2d\d+)\x3b\x22\d+\x3a\s+(\w+)\x3a\s+(\w+\s+\w+\s+\w+\s+\w+\s+\w+)\x22\x3b(\d+)\x3b\x22(\w+)\x22\x3b(\d{2}\x2e\d{3}\x2e\d{3}\x2e\d{3})\x3b(\d+)\x3b(\d{3}\x2e\d{3}\x2e\d{2}\x2e\d{3})\x3b(\d+)\x3b\d\x3b\d\w\x3b\d\w\x3b\d\x3b\d+\x3b\x22(\w+)\x22\x3b\d+\x3b\d+\x3b\s+\x3b\d+/; // Alternative syntax using RegExp constructor // const regex = new RegExp('(\\d{4}\\x2f\\d{2}\\x2f\\d{2}\\s+\\d{2}\\x3a\\d{2}\\x3a\\d{2})\\x2e\\d+\\s+(\\w+\\x2b\\d+\\x3a\\d+)\\s+(\\d{2}\\x2e\\d{3}\\x2e\\d{2}\\x2e\\d{3})\\s+(\\w{3}\\s+\\d+\\s+\\d{2}\\x3a\\d{2}\\x3a\\d{2})\\s+(\\w+\\x2e\\w+\\x2e\\w+\\x2e\\w+\\x2e\\w+)\\s+(\\d\\x3b\\d\\x3b\\w+\\x2d\\w+\\x2d\\w+\\x2d\\w+\\x2d\\w+)\\x3b(\\d+\\x2d\\d+\\x2d\\d+\\x2d\\d+\\x2d\\d+)\\x3b\\x22\\d+\\x3a\\s+(\\w+)\\x3a\\s+(\\w+\\s+\\w+\\s+\\w+\\s+\\w+\\s+\\w+)\\x22\\x3b(\\d+)\\x3b\\x22(\\w+)\\x22\\x3b(\\d{2}\\x2e\\d{3}\\x2e\\d{3}\\x2e\\d{3})\\x3b(\\d+)\\x3b(\\d{3}\\x2e\\d{3}\\x2e\\d{2}\\x2e\\d{3})\\x3b(\\d+)\\x3b\\d\\x3b\\d\\w\\x3b\\d\\w\\x3b\\d\\x3b\\d+\\x3b\\x22(\\w+)\\x22\\x3b\\d+\\x3b\\d+\\x3b\\s+\\x3b\\d+', '') const str = `2015/07/25 17:26:16.028 GMT+08:00 10.100.10.222 May 16 17:29:29 nipssmsdc2.hqlan.abc.com.my 8;3;92439f8d-86fa-4522-aeea-42e250b0fa05;00000001-0001-0001-0001-000000013012;"13012: SIP: SipVicious Brute Force SIP Tool";13012;"udp";62.210.248.238;5084;202.190.48.185;6060;1;4A;4B;7;11;"nips02dc1";16929789;1431768569067; ;95128847`; // 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