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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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

const regex = /^\"(?<timestart>\d{4}\/\d{2}\/\d{2}\s\d{2}\:\d{2}\:\d{2})?([\"|\,]*)?(?<recipient>[\w|\.|\-|_|\d]*@(?<domainimpacted>[\w|\.|\-|_|\d]*))?([\"|\,]*)?(?<subject>[\w|\s|\#|\@|\±|\§|\d|\!|\$|\%|\^|\,|\.|\(|\)|\[|\]|\{|\}|\:|\-|\&|\*|\'|\=|\+]*)?([\"|\,]*)?(?<action>\w*)?([\"|\,]*)?(?<sender>[\w|\.|\-|_|\d]*@(?<domainorigin>[\w|\.|\-|_|\d]*))?([\"|\,]*)?(?<account>[\w|\.|\-|_|\d|\,|\s]*)?([\"|\,]*)?(?<status>[\w|\.|\-|_|\d]*)?([\"|\,]*)?(?<object>[\w|\.|\-|_|\d]*)?([\"|\,]*)?(?<reason>[\w|\.|\-|_|\d]*)?([\"|\,]*)?(?<policy>[\w|\.|\-|_|\d]*)?([\"|\,]*)?(?<objecttype>[\w|\.|\-|_|\d|\s|\,]*)?([\"|\,]*)?(?<size>[\d]*)?([\"|\,]*)?(?<command>[\w|\.|\-|_|\d]*)?([\"|\,]*)?(?<objectname>[\w|\.|\-|_|\d]*)?([\"|\,]*)?(?<threatname>[\w|\.|\-|_|\d]*)?([\"|\,]*)?/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('^\\"(?<timestart>\\d{4}\\\/\\d{2}\\\/\\d{2}\\s\\d{2}\\:\\d{2}\\:\\d{2})?([\\"|\\,]*)?(?<recipient>[\\w|\\.|\\-|_|\\d]*@(?<domainimpacted>[\\w|\\.|\\-|_|\\d]*))?([\\"|\\,]*)?(?<subject>[\\w|\\s|\\#|\\@|\\±|\\§|\\d|\\!|\\$|\\%|\\^|\\,|\\.|\\(|\\)|\\[|\\]|\\{|\\}|\\:|\\-|\\&|\\*|\\\'|\\=|\\+]*)?([\\"|\\,]*)?(?<action>\\w*)?([\\"|\\,]*)?(?<sender>[\\w|\\.|\\-|_|\\d]*@(?<domainorigin>[\\w|\\.|\\-|_|\\d]*))?([\\"|\\,]*)?(?<account>[\\w|\\.|\\-|_|\\d|\\,|\\s]*)?([\\"|\\,]*)?(?<status>[\\w|\\.|\\-|_|\\d]*)?([\\"|\\,]*)?(?<object>[\\w|\\.|\\-|_|\\d]*)?([\\"|\\,]*)?(?<reason>[\\w|\\.|\\-|_|\\d]*)?([\\"|\\,]*)?(?<policy>[\\w|\\.|\\-|_|\\d]*)?([\\"|\\,]*)?(?<objecttype>[\\w|\\.|\\-|_|\\d|\\s|\\,]*)?([\\"|\\,]*)?(?<size>[\\d]*)?([\\"|\\,]*)?(?<command>[\\w|\\.|\\-|_|\\d]*)?([\\"|\\,]*)?(?<objectname>[\\w|\\.|\\-|_|\\d]*)?([\\"|\\,]*)?(?<threatname>[\\w|\\.|\\-|_|\\d]*)?([\\"|\\,]*)?', 'gm') const str = `"2020/04/07 08:26:21","shabbir.jafri@mcb.com.pk","REQUIRED ORIGINAL LC # 0054ILS200@!±026, MCB to MCB.(NOVATEX)","Accepted","ppta.treasury@lottechem.pk","None","None","None","Clean","None","Portable Document Format","131835","None","None","None" "2020/04/05 15:20:02","telecom.support@mcb.com.pk","MCB14005 Lhr: Gulberg Gelria - ATM Down","Accepted","Abbas.Zaheer@ncr.com","Zaheer, Abbas","Whitelisted","None","Spam","None","JPEG Interchange Format,JPEG Interchange Format,JPEG Interchange Format,JPEG Interchange Format","18837","None","None","None" "2020/04/07 08:27:02","narain.das@mcb.com.pk","New Doc 2020-04-07 13.25.15 - Page 1","Accepted","naraindas24@gmail.com","Narain Das","None","None","Clean","None","Portable Document Format","397990","None","None","None"`; // 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