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 = '/href="index\.php\?option=com_k2.*?(?=")/'; $str = '<p><a href="index.php?option=com_k2&view=item&id=6238:alias-title-of-an-article" target="_blank">Lorem ipsum dolor sit amet</a>, consectetur adipiscing elit. Donec sed consequat erat, eu interdum est. <a href="index.php?option=com_k2&view=item&id=6238:alias-title-of-an-article.html" target="_blank">Integer auctor</a>Nam sagittis vestibulum tortor non convallis. . Nulla pellentesque urna et urna accumsan, a accumsan nibh iaculis. Quisque faucibus sed arcu ac imperdiet. Duis pulvinar interdum libero, vel sodales lorem elementum sit amet. Sed ullamcorper vulputate metus, non pretium enim lacinia vel. Pellentesque gravida euismod lorem at scelerisque. Ut ultricies dolor dolor, quis luctus est cursus a. In vulputate, tortor vel ornare semper, sapien dolor rutrum augue, ut condimentum eros quam eget sapien. In sagittis ut mauris ut rutrum. Nulla sodales gravida nunc, et sollicitudin nisl viverra ut. Curabitur nec malesuada mauris. Mauris tempus mollis erat, vel euismod magna. Pellentesque habitant morbi tristique senectus et netus et malesuada fames ac turpis egestas.</p>'; preg_match_all($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