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 = '/(?:[^@^]++|[@^]{2,}+)(*SKIP)(*F)|(?<=([\x09-\x0D\x20\x85\xA0\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}\x21-\x22\x25-\x2A\x2C-\x2F\x3A\x3B\x3F\x5B-\x5D\x5F\x7B\x7D\xA1\xA7\xAB\xB6\xB7\xBB\xBF\x{037E}\x{0387}\x{055A}-\x{055F}\x{0589}\x{058A}\x{05BE}\x{05C0}\x{05C3}\x{05C6}\x{05F3}\x{05F4}\x{0609}\x{060A}\x{060C}\x{060D}\x{061B}\x{061E}\x{061F}\x{066A}-\x{066D}\x{06D4}\x{0700}-\x{070D}\x{07F7}-\x{07F9}\x{0830}-\x{083E}\x{085E}\x{0964}\x{0965}\x{0970}\x{0AF0}\x{0DF4}\x{0E4F}\x{0E5A}\x{0E5B}\x{0F04}-\x{0F12}\x{0F14}\x{0F3A}-\x{0F3D}\x{0F85}\x{0FD0}-\x{0FD4}\x{0FD9}\x{0FDA}\x{104A}-\x{104F}\x{10FB}\x{1360}-\x{1368}\x{1400}\x{166D}\x{166E}\x{169B}\x{169C}\x{16EB}-\x{16ED}\x{1735}\x{1736}\x{17D4}-\x{17D6}\x{17D8}-\x{17DA}\x{1800}-\x{180A}\x{1944}\x{1945}\x{1A1E}\x{1A1F}\x{1AA0}-\x{1AA6}\x{1AA8}-\x{1AAD}\x{1B5A}-\x{1B60}\x{1BFC}-\x{1BFF}\x{1C3B}-\x{1C3F}\x{1C7E}\x{1C7F}\x{1CC0}-\x{1CC7}\x{1CD3}\x{2010}-\x{2027}\x{2030}-\x{2043}\x{2045}-\x{2051}\x{2053}-\x{205E}\x{207D}\x{207E}\x{208D}\x{208E}\x{2308}-\x{230B}\x{2329}\x{232A}\x{2768}-\x{2775}\x{27C5}\x{27C6}\x{27E6}-\x{27EF}\x{2983}-\x{2998}\x{29D8}-\x{29DB}\x{29FC}\x{29FD}\x{2CF9}-\x{2CFC}\x{2CFE}\x{2CFF}\x{2D70}\x{2E00}-\x{2E2E}\x{2E30}-\x{2E44}\x{3001}-\x{3003}\x{3008}-\x{3011}\x{3014}-\x{301F}\x{3030}\x{303D}\x{30A0}\x{30FB}\x{A4FE}\x{A4FF}\x{A60D}-\x{A60F}\x{A673}\x{A67E}\x{A6F2}-\x{A6F7}\x{A874}-\x{A877}\x{A8CE}\x{A8CF}\x{A8F8}-\x{A8FA}\x{A8FC}\x{A92E}\x{A92F}\x{A95F}\x{A9C1}-\x{A9CD}\x{A9DE}\x{A9DF}\x{AA5C}-\x{AA5F}\x{AADE}\x{AADF}\x{AAF0}\x{AAF1}\x{ABEB}\x{FD3E}\x{FD3F}\x{FE10}-\x{FE19}\x{FE30}-\x{FE52}\x{FE54}-\x{FE61}\x{FE63}\x{FE68}\x{FE6A}\x{FF01}-\x{FF02}\x{FF05}-\x{FF0A}\x{FF0C}-\x{FF0F}\x{FF1A}\x{FF1B}\x{FF1F}\x{FF3B}-\x{FF3D}\x{FF3F}\x{FF5B}\x{FF5D}\x{FF5F}-\x{FF65}\x2B\x3C-\x3E\x5E\x60\x7C\x7E\xA8\xB1\xAF\xB4\xB8\x{02C2}-\x{02C5}\x{02DC}\x{02D2}\x{02DC}\x{02DD}\x{02DF}\x{0375}\x{0384}\x{1FEF}\x{1FFD}\x{1FFE}\x{2044}\x{2052}\x{207A}-\x{207C}\x{208A}-\x{208C}\x{A789}\x{FF0B}\x{FF1C}-\x{FF1E}\x{A490}\x{A4C6}\x{A789}\x{A78A}])|\^[cjleqrd])(\^[34biu78])*+@([a-z\d][\w-.]{0,25}[a-z\d])(\^[34biu78])*+(?=(?1))/i'; $str = 'All @User tags have to be matched. ((\\^[BIU34biu78])++)* can be added inside the rear lookahead, but that does more steps. (?(?=\\^[BIU34biu78])(?:\\^[BIU34biu78])++) can be used instead, but does more steps. This regex does 3 steps for any letter not allowed surrounding tags, and 7 steps for any punctuation or white space allowed. I didn\'t add ^| and |$ in the lookarrounds, I rather add spaces before parsing. Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. #lolll #@ _@User .@User lol#lol ###lolll gd@lool #lolll ##lolll .#lolll g^B^b@lools #lol ^B^b@User #lool ^B ^C@User g^c@user g @User^U, @User^u^B^b^I,wd tr^d yegd#lool Lorem ipsum dolor sit amet, consectetur Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. t@lollls @User.... Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ,,,,,,,,,,,,,,,ffffffffffffffffffffffffffffffffffffff ffffffffffffffffffffffffffffffffffffffffffffffffff. @@lolllláss. Lorem ipsum dolor sit amet, consectetur adipiscing elitt, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. @lolll@lolll@lolll@lolll@lolllk hththt @User Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. yeol#lol ###lolll gd#lool #lolll ##lolll .#lolll #lol#lol ###lolll gd#lool trt hrt tr hholis k t,al yey #lolll ##lolll .#lolll #lol#lol ###lolllia gd#lool trt .@User hrt tr hholgd#lool trt hrt tr hholis k tal yegd#lool trt hrt Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. #lolll #@ _@User .@User lol#lol ###lolll gd@lool Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. #lolll ##lolll .#lolll #lol hthththt @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ ,@User Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. ,,@,,hrt tr hholis k tal yeol trt hrt tr hholis k tal yeol#lol ###lolllia gd#lool trt hrt tr hholis k tal yey #lolll ##lolll .#lolll #lol#lol ###lolllia gd#lool trt @@@@@@@@@@@@@@@hththththththt @User #############################################################################################################################################################################################################lolll Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum. adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. yegd#.lool hththt '; 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