Regular Expressions 101

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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

/
/
gm

Test String

Code Generator

Language

Generated Code

$re = '/^(?:(?<initial_commit>Initial commit\.?)|(?<merge>Merge [^\r\n]+)|(?<type>build|chore|ci|docs|feat|fix|perf|refactor|revert|style|test|¯\\\\_\(ツ\)_\/¯)(?:\((?<scope>[\w-]+)\))?(?<breaking>!)?: (?<summary>[\w ,\'.`:-]+)(?<=\v\v){0,2}(?<body>[\w\s,\'.`\[\]-]+)(?<footer>(?<=\v\v)(?:(?<footer_token>[\w\s-]+): (?<footer_value>[\w -`]+))+|$))/m'; $str = '-------------- * Should PASS -------------- Initial commit. Merge pull request #123 from branch x.y.z :tada:. ¯\\_(ツ)_/¯: commit subject. # Commit message with description and breaking change footer feat: allow provided config object to extend other configs BREAKING CHANGE: `extends` key in config file is now used for extending other config files. # Commit message with ! to draw attention to breaking change feat!: send an email to the customer when a product is shipped. # Commit message with scope and ! to draw attention to breaking change feat(api)!: send an email to the customer when a product is shipped. # Commit message with both ! and BREAKING CHANGE footer chore!: drop support for Node 6 BREAKING CHANGE: use JavaScript features not available in Node 6. # Commit message with no body docs: correct spelling of CHANGELOG. # Commit message with scope feat(lang): :flag-eg: added `Arabic` language. # Commit message with multi-paragraph body and multiple footers refactor(api)!: :checkered_flag: prevent racing conditions of requests of the trusted borwsers. [patch] List of the changes, that has been introduced. - Introduce a request id and a reference to latest request. Dismiss incoming responses other than from latest request. - Remove timeouts which were used to mitigate the racing issue but are obsolete now. BREAKING CHANGE: Upgrading dependencies. Signed-off-by: Ahmed Kamal <architect@gmail.com> Reviewed-by: Z Tested-by: C Refs: #123 -------------- * Should FAIL -------------- build // Invalid end of line chore: // Invalid, subject is missing. ci(... is awesome // Invalid, closing of parenthesis. docs(v1) is boring // Invalid, missing colon. feat:of the giants. // Invalid, missing space. built: to last. // Invalid type. fix(multiple things): once and for all. // Invalid scope, multi-words. ¯\\_(ツ)_/¯[xys]:subject // Invalid scope parenthesis. Prefix build(api): no // Invalid beggining. '; preg_match_all($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