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

/
/
s

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

$re = '/^(<[^>]*>)*((?:\w+\W+){35})\w.*$/s'; $str = '<p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas vehicula lorem magna, sed commodo neque hendrerit eu. Aliquam vulputate tellus a tellus congue iaculis. Integer sit amet gravida leo. Ut hendrerit, massa non rutrum fringilla, justo sem sodales velit, vitae ornare odio mauris sed dui. Duis suscipit posuere neque vel gravida. Nam ullamcorper, justo maximus pretium iaculis, ipsum elit hendrerit turpis, eu convallis leo magna vitae neque. Praesent interdum eget quam quis ultricies.</p> <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Maecenas vehicula lorem magna, sed commodo neque hendrerit eu. Aliquam vulputate tellus a tellus congue iaculis. Integer sit amet gravida leo. Ut hendrerit, massa non rutrum fringilla, justo sem sodales velit, vitae ornare odio mauris sed dui. Duis suscipit posuere neque vel gravida. Nam ullamcorper, justo maximus pretium iaculis, ipsum elit hendrerit turpis, eu convallis leo magna vitae neque. Praesent interdum eget quam quis ultricies.</p>'; $subst = "$2"; $result = preg_replace($re, $subst, $str, 1); echo "The result of the substitution is ".$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