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

/
/
gi

Test String

Code Generator

Language

Generated Code

$re = '/\s*((\w+)=([\'\"])(.*?)\3)\1*/i'; $str = '<?xml version="1.0" encoding="UTF-8"?> <root-topic docid="10001048" docstatus="Draft" id="LegalConsiderations-17D8778D"><title>Legal Considerations</title> <shortdesc>Legal Considerations</shortdesc> <p product_type="accessories;chassis;enclosure;power supply">Video and audio surveillance can be regulated by laws that vary from country to country. Check the laws in your local region before using this product for surveillance purposes.</p> <p product_type="audio device">Audio surveillance can be regulated by laws that vary from country to country. Check the laws in your local region before using this product for surveillance purposes.</p> <p network_video_products="audio" product_type="network camera;video encoder;thermal camera;AVHS;ACM;ACS;application;O3C" >Video and audio surveillance can be regulated by laws that vary from country to country. Check the laws in your local region before using this product for surveillance purposes.</p> <p network_video_products="no audio" product_type="network camera;video encoder;thermal camera">Video surveillance can be regulated by laws that vary from country to country. Check the laws in your local region before using this product for surveillance purposes.</p> <p network_video_products="audio" product_type="network camera;video encoder;thermal camera">This product includes one (1) H.264 decoder license and one (1) AAC decoder license. To purchase further licenses, contact your reseller.</p> <p network_video_products="no audio" product_type="network camera;video encoder;thermal camera">This product includes one (1) H.264 decoder license. To purchase further licenses, contact your reseller.</p> <p product_type="thermal camera">This product is subject to export control regulations. You should always consult and comply with the regulations of the appropriate local export control authorities.</p> </root-topic> '; preg_match_all($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