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

/
/
gm

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

const regex = /\bdetails:.*?(\/.*?\.png\b)/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('\\bdetails:.*?(\\\/.*?\\.png\\b)', 'gm') const str = `'\\u001b[1m\\u001b[31m \\u001b[1m● \\u001b[1mregister page › register-automated › desktop › CONTROL\\u001b[39m\\u001b[22m\\n\\n Expected image to match or be a close match to snapshot but was 0.009980258828690502% different from snapshot (91 differing pixels).\\n \\u001b[1m\\u001b[31mSee diff for details:\\u001b[39m\\u001b[22m \\u001b[31m/src/pages/__image_snapshots__/__diff_output__/register-test-js-register-page-register-automated-desktop-control-1-diff.png\\u001b[39m\\n\\u001b[2m\\u001b[22m\\n\\u001b[2m \\u001b[0m \\u001b[90m 60 | \\u001b[39m\\u001b[0m\\u001b[22m\\n\\u001b[2m \\u001b[0m \\u001b[90m 61 | \\u001b[39m \\u001b[36mconst\\u001b[39m image \\u001b[33m=\\u001b[39m await page\\u001b[33m.\\u001b[39mscreenshot({ fullPage\\u001b[33m:\\u001b[39m isFullPage })\\u001b[33m;\\u001b[39m\\u001b[0m\\u001b[22m\\n\\u001b[2m \\u001b[0m\\u001b[31m\\u001b[1m>\\u001b[2m\\u001b[39m\\u001b[90m 62 | \\u001b[39m expect(image)\\u001b[33m.\\u001b[39mtoMatchImageSnapshot({threshold\\u001b[33m:\\u001b[39m \\u001b[35m0.3\\u001b[39m})\\u001b[33m;\\u001b[39m\\u001b[0m\\u001b[22m\\n\\u001b[2m \\u001b[0m \\u001b[90m | \\u001b[39m \\u001b[31m\\u001b[1m^\\u001b[2m\\u001b[39m\\u001b[0m\\u001b[22m\\n\\u001b[2m \\u001b[0m \\u001b[90m 63 | \\u001b[39m })\\u001b[33m;\\u001b[39m\\u001b[0m\\u001b[22m\\n\\u001b[2m \\u001b[0m \\u001b[90m 64 | \\u001b[39m\\u001b[0m\\u001b[22m\\n\\u001b[2m \\u001b[0m \\u001b[90m 65 | \\u001b[39m \\u001b[36mif\\u001b[39m(experimentName \\u001b[33m||\\u001b[39m experiementVariationName) {\\u001b[0m\\u001b[22m\\n\\u001b[2m\\u001b[22m\\n\\u001b[2m \\u001b[2mat Object.toMatchImageSnapshot (\\u001b[2msrc/command/getPageImageShot.js\\u001b[2m:62:25)\\u001b[2m\\u001b[22m\\n' `; const subst = `$1/`; // The substituted value will be contained in the result variable const result = str.replace(regex, subst); console.log('Substitution result: ', result);

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