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

/
/
mg

Test String

Code Generator

Language

Generated Code

$re = '/^P((((([0-9]+Y([0-9]+M)?([0-9]+[DW])?)|([0-9]+M([0-9]+[DW])?)|([0-9]+[DW]))(T(([0-9]+H([0-9]+M)?([0-9]+S)?)|([0-9]+M([0-9]+S)?)|([0-9]+S)))?|(T(([0-9]+H([0-9]+M)?([0-9]+S)?)|([0-9]+M([0-9]+S)?)|([0-9]+S)))))|(([0-9]{4}-(0[0-9]|1[0-2])-([0-2][0-9]|3[0-1]))T(([0-1][0-9]|2[0-3]):[0-5][0-9]:[0-5][0-9])))$/m'; $str = 'P0Y1M2DT3H4M5S P0Y1M2WT3H4M5S P0Y1M2DT3H P0YT3H4M5S P0YT3H P0Y1M2D P0Y'; preg_match_all($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