Regular Expressions 101

Save & Share

  • Regex Version: ver. 4
  • 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

/
/
gU

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

$re = '/<a(.*)href="([^"]*)"(.*)>/U'; $str = '<p><b>Piano:</b><br /></p><p><a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3374"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2302.jpg" alt="Griglie in ghisa" title="Griglie in ghisa" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3368"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2300.jpg" alt="Bruciatore Ultrarapido" title="Bruciatore Ultrarapido" /></a> <br /></p><p class="dot">7 bruciatori a gas, di cui 1 Ultrarapido (4,2 kW)<br /></p><p><br /></p><p><b>Forno principale, superiore:</b><br /></p><p><a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3372"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/A.jpg" alt="A" title="A" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/4225"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func1548.jpg" alt="4 livelli di cottura" title="4 livelli di cottura" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3369"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2320.jpg" alt="Smalto Ever Clean" title="Smalto Ever Clean" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3665"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func1518.jpg" alt="Volta Mobile" title="Volta Mobile" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3371"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2318.jpg" alt="Interno porta tuttovetro" title="Interno porta tuttovetro" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3671"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2316.jpg" alt="Vetro interno rimovibile" title="Vetro interno rimovibile" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3373"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2314.jpg" alt="Porta a triplo vetro" title="Porta a triplo vetro" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3370"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2324.jpg" alt="Raffreddamento tangenziale" title="Raffreddamento tangenziale" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3675"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2328.jpg" alt="Guide telescopiche" title="Guide telescopiche" /></a> <br /></p><p class="dot">Forno elettrico multifunzione termoventilato, 7 funzioni<br /></p><p>compresa funzione di pulizia Vapor Clean<br /></p><p class="dot">Opzione programmazione di inizio e fine cottura con allarme<br /></p><p>acustico di fine cottura<br /></p><p class="dot">Display / Orologio: elettronico a 5 tasti<br /></p><p><b>Forno secondario, inferiore:</b><br /></p><p><a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3372"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/A.jpg" alt="A" title="A" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/4225"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func1548.jpg" alt="4 livelli di cottura" title="4 livelli di cottura" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3369"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2320.jpg" alt="Smalto Ever Clean" title="Smalto Ever Clean" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3665"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func1518.jpg" alt="Volta Mobile" title="Volta Mobile" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3371"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2318.jpg" alt="Interno porta tuttovetro" title="Interno porta tuttovetro" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3671"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2316.jpg" alt="Vetro interno rimovibile" title="Vetro interno rimovibile" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3373"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2314.jpg" alt="Porta a triplo vetro" title="Porta a triplo vetro" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3370"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2324.jpg" alt="Raffreddamento tangenziale" title="Raffreddamento tangenziale" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3675"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2328.jpg" alt="Guide telescopiche" title="Guide telescopiche" /></a> <br /></p><p class="dot">Forno elettrico multifunzione ventilato, 7 funzioni<br /></p><p>compresa funzione di pulizia Vapor Clean<br /></p><p><b>Forno ausiliario, superiore:</b><br /></p><p><a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/4710"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func1552.jpg" alt="2 livelli di cottura" title="2 livelli di cottura" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3369"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2320.jpg" alt="Smalto Ever Clean" title="Smalto Ever Clean" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3665"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func1518.jpg" alt="Volta Mobile" title="Volta Mobile" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3371"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2318.jpg" alt="Interno porta tuttovetro" title="Interno porta tuttovetro" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3671"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2316.jpg" alt="Vetro interno rimovibile" title="Vetro interno rimovibile" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3373"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2314.jpg" alt="Porta a triplo vetro" title="Porta a triplo vetro" /></a> <a class="dialog function_link" dclass="function_dialog" dwidth="500" dheight="auto" href="http://www.smeg.it/ajax/view_function/3370"><img src="http://www.smeg.it/smeg_it/images/functions/0/0/Func2324.jpg" alt="Raffreddamento tangenziale" title="Raffreddamento tangenziale" /></a> <br /></p><p class="dot">Forno elettrico 1 funzione<br /></p><p><br /></p><p class="dot">Vano portaoggetti con apertura a cassetto<br /></p><p class="dot"><b>Porta dei forni principale e secondario con apertura <br /></p><p>laterale</b><br /></p><p class="dot">DIMENSIONI: LxPxH 110x60x91 cm</p>'; $subst = "<a$1href=\"javascript:alert(\'Test\');\"$3>"; $result = preg_replace($re, $subst, $str); echo "The result of the substitution is ".$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 PHP, please visit: http://php.net/manual/en/ref.pcre.php