Regular Expressions 101

Save & Share

  • Regex Version: ver. 2
  • 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

Code Generator

Language

Generated Code

re = /^(((0|[1-9]\d*)\.)(((0|[1-9]\d*|x)\.)?x)|main|next(-major)?|beta|alpha)$/m str = 'Inspired by Semantic Release Distributions Channels from Branches: https://semantic-release.gitbook.io/semantic-release/usage/configuration#branches Valid Semantic Release Distribution Channels: 0.0.x 0.x.x 0.x 1.2.x 1.x.x 1.x 10.20.x 10.x.x 10.x 1.0.x 2.0.x 2.x.x 2.x 1.1.x 99999999999999999999999.999999999999999999.x 99999999999999999999999.x.x 99999999999999999999999.x main next next-major beta alpha Inalid Semantic Release Distribution Channels: x 0. 0.xx 00.0.x 1.2 01.x 1.02.x 1.x.0 x.20.x x.x.x x.0.x 2.0.x-alpha 2.0.x+meta x.x 01.1.x 99999999999999999999999.0999999999999999999.x 099999999999999999999999.x.x mains pre-next next-minor beta+ -alpha gamma ' # Print the match result str.scan(re) do |match| puts match.to_s end

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 Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html