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

re = /@@.*(?:[\s\r]?(?!\s*\^).*)*/ str = '^0001 HeadOne @@ Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been theindustry\'s standard dummy text ever since the 1500s, when an unknown printer took a galley of typeand scrambled it to make a type specimen book. ^0002 HeadTwo @@ Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been theindustry\'s standard dummy text ever since the 1500s, when an unknown printer took a galley of typeand scrambled it to make a type specimen book. Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been theindustry\'s standard dummy text ever since the 1500s, when an unknown printer took a galley of typeand scrambled it to make a type specimen book. ^004 HeadFour @@ Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry\'s standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. ^0004 HeadFour @@ Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been theindustry\'s standard dummy text ever since the 1500s, when an unknown printer took a galley of typeand scrambled it to make a type specimen book. Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been theindustry\'s standard dummy text ever since the 1500s, when an unknown printer took a galley of typeand scrambled it to make a type specimen book.' # 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