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

/
/
gmi

Test String

Code Generator

Language

Generated Code

const regex = /^((401178|401179|431274|438935|451416|457393|457631|457632|504175|627780|636297|636369|(506699|5067[0-6]\d|50677[0-8])|(50900\d|5090[1-9]\d|509[1-9]\d{2})|65003[1-3]|(65003[5-9]|65004\d|65005[0-1])|(65040[5-9]|6504[1-3]\d)|(65048[5-9]|65049\d|6505[0-2]\d|65053[0-8])|(65054[1-9]|6505[5-8]\d|65059[0-8])|(65070\d|65071[0-8])|65072[0-7]|(65090[1-9]|65091\d|650920)|(65165[2-9]|6516[6-7]\d)|(65500\d|65501\d)|(65502[1-9]|6550[3-4]\d|65505[0-8]))[0-9]{10,12})/gmi; // Alternative syntax using RegExp constructor // const regex = new RegExp('^((401178|401179|431274|438935|451416|457393|457631|457632|504175|627780|636297|636369|(506699|5067[0-6]\\d|50677[0-8])|(50900\\d|5090[1-9]\\d|509[1-9]\\d{2})|65003[1-3]|(65003[5-9]|65004\\d|65005[0-1])|(65040[5-9]|6504[1-3]\\d)|(65048[5-9]|65049\\d|6505[0-2]\\d|65053[0-8])|(65054[1-9]|6505[5-8]\\d|65059[0-8])|(65070\\d|65071[0-8])|65072[0-7]|(65090[1-9]|65091\\d|650920)|(65165[2-9]|6516[6-7]\\d)|(65500\\d|65501\\d)|(65502[1-9]|6550[3-4]\\d|65505[0-8]))[0-9]{10,12})', 'gmi') const str = `5090402132456747 6500311231321321 6500321231321321 6500331231321321 6500341231321321 6500351231321321 6500391231321321 6500401231321321 6500451231564654 6500511231564654 6504051231321331 6504851231321321 6505411231321313 6507001321321313 6507201231321133 6509011235646432 5066998786245463 6516527887324132 6550007896242321 `; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // 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