Regular Expressions 101

Save & Manage Regex

  • Current Version: 1
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
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
Processing...

Test String

Code Generator

Language

Generated Code

const regex = /(?:RTDM_Thread_Pool)",(?:"\w+":"[0-9A-Za-z-_]{1,}",){1,}"__value_string__":"[^"]+?metric=\'(rtmsasrtdm01.\w+ActiveThreads)/; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?:RTDM_Thread_Pool)",(?:"\\w+":"[0-9A-Za-z-_]{1,}",){1,}"__value_string__":"[^"]+?metric=\\\'(rtmsasrtdm01.\\w+ActiveThreads)', '') const str = `{"annotations":{"DominosAlarm":"RTDM_Thread_Pool","__alertId__":"72","__alertScreenshotToken__":"d011471d-3947-409b-8ea4-d74bfb288d11","__dashboardUid__":"Do8Yh3jmk","__panelId__":"2","__value_string__":"[ var='A2' metric='rtmcrtsasrtdm01.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A3' metric='rtmcrtsasrtdm01.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A4' metric='rtmcrtsasrtdm01.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A5' metric='rtmcrtsasrtdm02.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A6' metric='rtmcrtsasrtdm02.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A7' metric='rtmcrtsasrtdm02.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A8' metric='rtminfsasrtdm01.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A9' metric='rtminfsasrtdm01.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A10' metric='rtminfsasrtdm01.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A11' metric='rtminfsasrtdm02.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A12' metric='rtminfsasrtdm02.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A13' metric='rtminfsasrtdm02.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A14' metric='rtmsasrtdm01.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A15' metric='rtmsasrtdm01.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A16' metric='rtmsasrtdm01.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A17' metric='rtmsasrtdm02.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A18' metric='rtmsasrtdm02.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A19' metric='rtmsasrtdm02.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A20' metric='rtmsasrtdm03.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A21' metric='rtmsasrtdm03.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A22' metric='rtmsasrtdm03.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A23' metric='rtmsasrtdm04.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A24' metric='rtmsasrtdm04.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A25' metric='rtmsasrtdm04.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A26' metric='rtmsasrtdm05.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A27' metric='rtmsasrtdm05.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A28' metric='rtmsasrtdm05.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A29' metric='rtmsasrtdm06.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A30' metric='rtmsasrtdm06.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A31' metric='rtmsasrtdm06.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A32' metric='NoData' labels={} value=null ]"},"endsAt":"2022-08-15T14:51:09.011+03:00","fingerprint":"07a1142e17b266ce","receivers":[{"name":"autogen-contact-point-default"}],"startsAt":"2022-08-15T14:48:09.011+03:00","status":{"inhibitedBy":[],"silencedBy":[],"state":"active"},"updatedAt":"2022-08-15T14:48:15.951+03:00","generatorURL":"http://rtmsasanalys01.msk.mts.ru:3000/alerting/grafana/UzwGQ2kVz/view","labels":{"Trigger":"[ var='A0' metric='NoData' labels={} value=null ], [ var='A1' metric='NoData' labels={} value=null ], [ var='A2' metric='rtmcrtsasrtdm01.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A3' metric='rtmcrtsasrtdm01.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A4' metric='rtmcrtsasrtdm01.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A5' metric='rtmcrtsasrtdm02.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A6' metric='rtmcrtsasrtdm02.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A7' metric='rtmcrtsasrtdm02.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A8' metric='rtminfsasrtdm01.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A9' metric='rtminfsasrtdm01.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A10' metric='rtminfsasrtdm01.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A11' metric='rtminfsasrtdm02.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A12' metric='rtminfsasrtdm02.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A13' metric='rtminfsasrtdm02.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A14' metric='rtmsasrtdm01.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A15' metric='rtmsasrtdm01.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A16' metric='rtmsasrtdm01.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A17' metric='rtmsasrtdm02.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A18' metric='rtmsasrtdm02.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A19' metric='rtmsasrtdm02.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A20' metric='rtmsasrtdm03.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A21' metric='rtmsasrtdm03.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A22' metric='rtmsasrtdm03.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A23' metric='rtmsasrtdm04.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A24' metric='rtmsasrtdm04.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A25' metric='rtmsasrtdm04.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A26' metric='rtmsasrtdm05.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A27' metric='rtmsasrtdm05.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A28' metric='rtmsasrtdm05.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A29' metric='rtmsasrtdm06.ActivityThreadPool_ActiveThreads' labels={} value=null ], [ var='A30' metric='rtmsasrtdm06.JdbcOracle_ActiveThreads' labels={} value=null ], [ var='A31' metric='rtmsasrtdm06.JdbcSastkts_ActiveThreads' labels={} value=null ], [ var='A32' metric='NoData' labels={} value=null ]","__alert_rule_uid__":"UzwGQ2kVz","alertname":"RTDM Thread Pool alert","rule_uid":"UzwGQ2kVz"}}`; // 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