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

/
/
gm

Test String

Code Generator

Language

Generated Code

const regex = /^[0]{1}[12345689]{1}[0-9]{1}[0-9]{7}$/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('^[0]{1}[12345689]{1}[0-9]{1}[0-9]{7}$', 'gm') const str = `0112440767 0112575409 0112324846 0112434545 0112574651 0112421395 0112914215 0112447378 0112687141 0112431766 0114817240 0112810828 0112573296 0112580403 0112502437 0112449460 0112347856 0112421299 0112685633 0112575659 0112522545 0112330446 0112508512 0112692055 0112449631 0112336517 0112324924 0112335561 0112435306 0112436644 0112501030 0112522549 0112685773 0112686691 0112431174 0372238001 0112431405 0112432681 0112584173 0112584961 0112421464 0112320052 0112596747 0112324724 0112448612 0112433022 0112422473 0112338162 0112508100 0112438836 0112329161 0112440591 0112986417 0112435780 0372224138 0112431000 0112335836 0112301337 0112437936 0112334624 0112588884 0112432575 0112434683 0112589489 0372229141 0112503650 0112325225 0112330523 0112431531 0112434047 0112433495 0112325473 0112436311 0112323014 0112593973 0112582785 0112433286 0112502016 0112446699 0112816053`; // 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