Regular Expressions 101

Save & Share

  • Regex Version: ver. 1
  • Fork 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

/
/
gm

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

$re = '/.*?(https?:[^"]+)(?(?!.*?https?:).*)/m'; $str = '[{"participants": ["minanageh379", "xcsadc"], "conversation": [{"sender": "minanageh379", "created_at": "2019-04-12T12:51:56.560361+00:00", "media": "https://scontent-lax3-1.cdninstagram.com/vp/edddf95178aca7bf75930ab8698ee45b/5D45203B/t51.2885-15/fr/e15/s1080x1080/55823673_114448266206459_7321604432125975069_n.jpg?_nc_ht=scontent-lax3-1.cdninstagram.com&ig_cache_key=Mjg2ODYwNDMxNzU3OTI1MTE1NTAxNjQ1NTk5MDkwOTMzNzY%3D.2"}, {"sender": "minanageh379", "created_at": "2019-04-12T12:51:51.923138+00:00", "text": "sd"}, {"sender": "minanageh379", "created_at": "2019-04-12T12:51:41.689524+00:00", "text": "sdsa"}, {"sender": "xcsadc", "created_at": "2019-04-12T12:50:57.283147+00:00", "text": "👩‍❤️‍💋‍👩"}, {"sender": "xcsadc", "created_at": "2019-04-12T12:39:35.248517+00:00", "text": "czx"}, {"sender": "xcsadc", "created_at": "2019-04-12T12:39:34.352752+00:00", "text": "dsad"}, {"sender": "xcsadc", "created_at": "2019-04-12T12:39:30.889023+00:00", "media": "https://scontent-lax3-1.cdninstagram.com/vp/e985406d6eac06bb11c2d6052c1821a2/5D508106/t51.2885-15/e15/s640x640/56218099_577906226037731_8663356006073884002_n.jpg?_nc_ht=scontent-lax3-1.cdninstagram.com&ig_cache_key=Mjg2ODYwMjk0MjA1ODQxNzYzNjM1OTI1ODMwMjYzMTExNjg%3D.2"}, {"sender": "xcsadc", "created_at": "2019-04-12T12:38:54.823472+00:00", "text": "hi hi hi"}, {"sender": "ncccy", "created_at": "2019-01-28T17:09:29.216184+00:00", "media": "https://scontent-lax3-1.cdninstagram.com/vp/57c43d748xcasc1abf58c890c5a6df042/5D199AE8/t51.2885-15/e15/p480x480/49913269_2181952555454636_8892094125900591548_n.jpg?_nc_ht=scontent-lax3-1.cdninstagram.com&ig_cache_key=Mjg1NjgsdasdAwNjgxNTk1OTY0OTIwMTA1NTMzNDQ%3D.2"}, {"sender": "ny", "created_at": "2017-10-22T20:49:50.042588+00:00", "media": "https://scontent-lax3-1.cdninstagram.com/vp/19d94ea45c2102a0f7c97838ef546b93/5D14B3C3/t51.2885-15/e15/22708873_149637425772501_5029503881546039296_n.jpg?_nc_ht=scontent-lax3-1.cdninstagram.com&ig_cache_key=Mjc4MzA3MDIyMTI3NDE3Njc3NTQxNTM1NTI2MjQyMjIyMDg%3D.2"}, {"sender": "xcsadc", "created_at": "2019-04-12T12:39:35.248517+00:00", "text": "czx"}]}]'; $subst = "$1\n\n"; $result = preg_replace($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