Regular Expressions 101

Save & Share

  • Regex Version: ver. 1
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

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

/
/
g

Test String

Code Generator

Language

Generated Code

const regex = /MWTTanDeltaValues=\s*([\s\S]+)(?=MWTTanDeltaTimeValues=)/g; // Alternative syntax using RegExp constructor // const regex = new RegExp('MWTTanDeltaValues=\\s*([\\s\\S]+)(?=MWTTanDeltaTimeValues=)', 'g') const str = `MWTTanDeltaMean=27.0355 MWTTanDeltaSTD=2.3498 MWTTanDeltaChangeOverTime=1.8083 MWTTanDeltaDuration= 15 MWTTanDeltaMeanPeakVoltage=34475.3700 MWTTanFrequency=0.1000 MWTTanDeltaValues= 27.5766;27.5707;27.3737;26.6112;26.0126;26.2416;26.1120; 26.1621;25.7420;25.9710;25.6238;25.7683;25.8689;26.1269; 26.1321;26.2643;25.7848;25.1501;25.3091;25.0000;25.3175; 25.5920;24.8733;24.6167;24.6299;24.7430;25.4183;25.9896; 25.4958;25.4259;26.4650;25.7657;30.0259;30.5261;30.2207; 30.7683;30.5524;31.4316;30.5092;31.2188;31.3513;31.4804; 31.1870;31.5287;31.2671;30.7482;29.5514;28.6546;29.6851; 29.2009;29.2151;29.1309;29.1466;33.0232;31.8877;30.4890; 26.8053;27.0559;26.8480;25.6997;25.8613;26.7863;26.0611; 26.7878;27.2462;25.6071;25.9075;25.9302;25.8017;26.8502; 26.7850;26.3517;25.5865;26.1033;25.8408;26.2310;25.0309; 23.9557;24.0468;24.0217;23.7751;24.5628;24.3670;24.3429; 25.5378;27.6765;24.4876;24.7278;23.9403; MWTTanDeltaTimeValues= 25.8168;27.8008;27.0355; MWTTanDeltaSTDTimeValues= 0.7685;2.4520;2.3498; MWTTanDeltaChangeTimeValues= [Result] SmileyPhase1=3 Temperature= MeasurementResult=0 TEST SEQUENCE COMPLETED SUCCESSFULLY 2017-12-27 14.08`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // 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