Regular Expressions 101

Save & Manage Regex

  • Current Version: 1
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
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
Processing...

Test String

Code Generator

Language

Generated Code

$re = '/graphiceq\s*:((?:\s*\d++(?:,\d++)?+(?:\.\d++)?+\s++[+-]?+\d++(?:\.\d++)?+[ \t]*+(?:;|$))++)/im'; $str = '# A 15-band graphic equalizer with ISO bands GraphicEQ: 25 6; 40 4.5; 63 3; 100 1.5; 160 0; 250 0; 400 0; 630 0; 1000 0; 1600 0; 2500 0; 4000 0; 6300 1.5; 10,000 +3; 16,000 +3 # A custom graphic equalizer GraphicEQ: 20.00 0.00; 25.00 -1.75; 30.00 -3.20; 35.00 -4.15; 40.00 -4.90; 45.00 -5.55; 50.00 -6.10; 60.00 -6.90; 70.00 -7.40; 80.00 -7.80; 90.00 -8.10; 100.00 -8.30 The regex used is more permissive than the original specification (https://sourceforge.net/p/equalizerapo/wiki/Configuration%20reference/#graphiceq-since-version-10): - Gain value can be signed (+/-); - Frequency can use a comma as thousand separator The last class does not include the newline as whitespaces to allow matching the `$` as the end of line (multiline flag is used).'; preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0); // Print the entire match result var_dump($matches);

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 PHP, please visit: http://php.net/manual/en/ref.pcre.php