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

r"
"
gm

Test String

Code Generator

Language

Generated Code

$re = '/\b(?:a*(?:ha*){2,}h?)\b|\b(?:a*(?:ja*)+j?)\b|\b(?:e*(?:je*)+j?)\b|\b(?:i*(?:ji+)+j?)\b|\b(?:A*(?:JA+)+J?)\b|\b(?:A*(?:HA+)+H?)\b|\b(?:e*(?:he+){2,}h?)\b|\b(?:Ja*(?:ja+)+j?)\b|\b(?:Je*(?:je+)+j?)\b|\bJa+\b|\b(?:Ji*(?:ji+)+j?)\b|\b(?:Ha*(?:ha+)+h?)\b|\b(?:Jo*(?:jo+)+j?)\b|\b(?:o*(?:jo+)+j?)\b|\b(?:a*((?:ja+)|(?:js+))+j?)\b|\b(?:A*((?:JA+)|(?:JS+))+J?)\b/m'; $str = 'jajajajajaja jejejejeje jijijijijij ji ja je hahahahahahaaaaa Hahahaaa Hahaaahaaha hahaahaaaah haaaaahaaahahahaaaaah heheeheheeeeheeeheh jajajaj jaja ja jejejej jeje je jijijiji jiji ji ajajajaja ahahahaha ejejejeje aaajajaja jajaaajajaaajaaaa JAJAJAJAJAJAJAJ HAHAHAHAAAAHAHAHAHAAA Hahahahahaha JAJAJAJA AAJAJAJA JAJAAAJAJAJAAAAJ he hehe haha ha has hamaca Jajajajaja Jaja Jejejejejeje Jaa Jijijijiiiiji jiiijijijiiijijijiii Jojojojojoj jojojoj Hahaa Jejeee jajaaaa Jajaaaa jajaj jajajajsjaja jajajssjsjsjajsja jsjsjsjsjsjsj JAJAJSJAJSSJAJSJSJAJSSSSJ '; preg_match_all($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