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
  • 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

/
/
g

Test String

Code Generator

Language

Generated Code

$re = '/<!-- @\[(?<component>[\w+]+)\(*(?<classes>[\w+]+)*\)*\] -->/'; $str = '<!-- @[Hero] --> # Creating new contexts <!-- @[UsageExample] --> ## Usage example ```javascript Import { ICON_NAME } from \'Icons\' ``` <!-- @[/Hero] --> <!-- @[ArticleSection] --> ## Section Title ### Section subtitle that contains additional information Cillum ipsum ad veniam elit non. Sunt ea ut quis qui dolore id voluptate magna. Ex non commodo reprehenderit ipsum irure. Ad excepteur nulla ullamco et deserunt magna et sint reprehenderit sint esse commodo. Tempor duis anim nisi commodo incididunt ut ex et sunt laborum excepteur ea culpa laborum. <!-- @[NoteBlock(warning)] --> > #### Be Careful > Eu laboris eiusmod ut exercitation minim laboris ipsum magna consectetur est [commodo](/nope). <!-- @[/NoteBlock] --> Officia esse Lorem ad duis dolore nostrud ex elit aliqua incididunt sint ad ex. Eiusmod do in ad aute nulla eiusmod tempor Lorem non. Qui sunt voluptate laborum mollit elit adipisicing minim dolore voluptate veniam incididunt proident ullamco. Ipsum est cupidatat occaecat pariatur ut aute. <!-- @[CodeExample] --> #### Code example ```javascript class ScrollingList extends React.Component { constructor(props) { super(props); this.listRef = React.createRef(); } render() { return ( &#60;div ref={this.listRef}&#62;{/* ...contents... */}&#60;/div&#62; ); } } ``` <!-- @[PropsTable] --> #### Props Prop Name | Value | Required --------- | ----- | -------- **label** | `{String}` | true **state** | `default` `secondary` `info` `warning` `danger` | false **size** | `xs` `s` `m` `l` `xl` | false **disabled** | `-` | false <!-- @[/ArticleSection] --> '; preg_match_all($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