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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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

$re = '/BEGIN:VEVENT DTEND;VALUE=DATE:(.*?) DTSTART;VALUE=DATE: (.*?) UID:(.*?) SUMMARY:(.*?) END:VEVENT/mi'; $str = 'BEGIN:VCALENDAR PRODID;X-RICAL-TZSOURCE=TZINFO:-//Airbnb Inc//Hosting Calendar 0.8.8//EN CALSCALE:GREGORIAN VERSION:2.0 BEGIN:VEVENT DTEND;VALUE=DATE:20221105 DTSTART;VALUE=DATE: 20220831 UID:6fec1092d3fa-a701f68d2829d331bc90b193830d447d@airbnb.com SUMMARY:Airbnb (Not available) END:VEVENT BEGIN:VEVENT DTEND;VALUE=DATE:20230103 DTSTART;VALUE=DATE:20221227 UID:6fec1092d3fa-e3596dc423d3ebfc6717c45d59f237ec@airbnb.com SUMMARY:Airbnb ( Not available) END:VEVENT BEGIN:VEVENT DTEND;VALUE=DATE:20230311 DTSTART;VALUE=DATE:20230212 UID:6fec1092d3fa-db18d3df7f07179688122eb867e2e274@airbnb.com SUMMARY:Airbnb (Not available) END:VEVENTDATE BEGIN:VEVENT= DTEND :20230903 DTSTART;VALUE=DATE:20230701 UID:6fec1092d3fa-de03b88cfd4d214ed4890da8da3a3541@airbnb.com SUMMARY:Airbnb (Not available) END:VEVENT END:VCALENDAR'; preg_match_all($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