Regular Expressions 101

Save & Manage Regex

  • Current Version: 2
  • 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
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

const regex = /Hagestein boven.+?(?:<td>Waterhoogte<\/td><td>)(.\d*)/; // Alternative syntax using RegExp constructor // const regex = new RegExp('Hagestein boven.+?(?:<td>Waterhoogte<\\\/td><td>)(.\\d*)', '') const str = `>H10</td><td><a target="_blank" href = "http://www.rws.nl/images/GRAVBVN_tcm174-335817.pdf">meer</a></td></tr><tr><td><a href='awd.php?mode=html&amp;projecttype=waterstanden&amp;category=1&amp;loc=GREB&amp;net=LMW'>Grebbe</a></td><td>21/04 17:30</td><td>Waterhoogte</td><td>643</td><td>cm NAP</td><td>LMW</td><td>GREB</td><td>H10</td><td></td></tr><tr><td><a href='awd.php?mode=html&amp;projecttype=waterstanden&amp;category=1&amp;loc=GREV&amp;net=LMW'>Grevenbicht</a></td><td>21/04 17:30</td><td>Waterhoogte</td><td>2623</td><td>cm NAP</td><td>LMW</td><td>GREV</td><td>H10</td><td><a target="_blank" href = "http://www.rws.nl/images/GREVBT_tcm174-335691.pdf">meer</a></td></tr><tr><td><a href='awd.php?mode=html&amp;projecttype=waterstanden&amp;category=1&amp;loc=GRPO&amp;net=LMW'>Groene Riv Pannerden ben</a></td><td>21/04 17:30</td><td>Waterhoogte</td><td>1143</td><td>cm NAP</td><td>LMW</td><td>GRPO</td><td>H10</td><td></td></tr><tr><td><a href='awd.php?mode=html&amp;projecttype=waterstanden&amp;category=1&amp;loc=GRPB&amp;net=LMW'>Groene Riv Pannerden bov</a></td><td>21/04 17:30</td><td>Waterhoogte</td><td>1153</td><td>cm NAP</td><td>LMW</td><td>GRPB</td><td>H10</td><td></td></tr><tr><td><a href='awd.php?mode=html&amp;projecttype=waterstanden&amp;category=1&amp;loc=HAAN&amp;net=LMW'>Haandrik Kruisbrug</a></td><td>21/04 17:30</td><td>Waterhoogte</td><td>910</td><td>cm NAP</td><td>LMW</td><td>HAAN</td><td>H10</td><td></td></tr><tr><td><a href='awd.php?mode=html&amp;projecttype=waterstanden&amp;category=1&amp;loc=HAGO&amp;net=LMW'>Hagestein beneden</a></td><td>21/04 17:30</td><td>Waterhoogte</td><td>98</td><td>cm NAP</td><td>LMW</td><td>HAGO</td><td>H10</td><td><a target="_blank" href = "http://www.rws.nl/images/HAGSBNDN_tcm174-335693.pdf">meer</a></td></tr><tr><td><a href='awd.php?mode=html&amp;projecttype=waterstanden&amp;category=1&amp;loc=HAGB&amp;net=LMW'>Hagestein boven</a></td><td>21/04 17:30</td><td>Waterhoogte</td><td>272</td><td>cm NAP</td><td>LMW</td><td>HAGB</td><td>H10</td><td><a target="_blank" href = "http://www.rws.nl/images/HAGSBVN_tcm174-335697.pdf">meer</a></td></tr><tr><td><a href='awd.php?mode=html&amp;projecttype=waterstanden&amp;category=1&amp;loc=HANS&amp;net=LMW'>Hansweert</a></td><td>21/04 17:30</td><td>Waterhoogte</td><td>180</td><td>cm NAP</td><td>LMW</td><td>HANS</td><td>H10</td><td><a target="_blank" href = "http://www.rws.nl/images/HANSWT_tcm174-335699.pdf">meer</a></td></tr><tr><td><a href='awd.php?mode=html&amp;projecttype=waterstanden&amp;category=1&amp;loc=HAWIb&amp;net=LMW'>Hansweert wind (b)</a></td><td>21/04 17:30</td><td>Waterhoogte</td><td>179</td><td>cm NAP</td><td>LMW</td><td>HAWIb</td><td>H10</td><td></td></tr><tr><td><a href='awd.php?m`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; if ((m = regex.exec(str)) !== null) { // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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 JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions