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 = '/(?!&\w{1,8};)&/'; $str = '<a href="http://www.testassociation.com/test.html?ab=5&compac=3&cd=5&ab=c" target="_blank">Customer Association</a>&amp; &quot; &amp; &apos; &lt; &gt; &nbsp; &iexcl; &cent; &pound; &curren; &yen; &brvbar; &sect; &uml; &copy; &ordf; &laquo; &not; &shy; &reg; &macr; &deg; &plusmn; &sup2; &sup3; &acute; &micro; &para; &middot; &cedil; &sup1; &ordm; &raquo; &frac14; &frac12; &frac34; &iquest; &Agrave; &Aacute; &Acirc; &Atilde; &Auml; &Aring; &AElig; &Ccedil; &Egrave; &Eacute; &Ecirc; &Euml; &Igrave; &Iacute; &Icirc; &Iuml; &ETH; &Ntilde; &Ograve; &Oacute; &Ocirc; &Otilde; &Ouml; &times; &Oslash; &Ugrave; &Uacute; &Ucirc; &Uuml; &Yacute; &THORN; &szlig; &agrave; &aacute; &acirc; &atilde; &auml; &aring; &aelig; &ccedil; &egrave; &eacute; &ecirc; &euml; &igrave; &iacute; &icirc; &iuml; &eth; &ntilde; &ograve; &oacute; &ocirc; &otilde; &ouml; &divide; &oslash; &ugrave; &uacute; &ucirc; &uuml; &yacute; &thorn; &yuml; &OElig; &oelig; &Scaron; &scaron; &Yuml; &fnof; &circ; &tilde; &Alpha; &Beta; &Gamma; &Delta; &Epsilon; &Zeta; &Eta; &Theta; &Iota; &Kappa; &Lambda; &Mu; &Nu; &Xi; &Omicron; &Pi; &Rho; &Sigma; &Tau; &Upsilon; &Phi; &Chi; &Psi; &Omega; &alpha; &beta; &gamma; &delta; &epsilon; &zeta; &eta; &theta; &iota; &kappa; &lambda; &mu; &nu; &xi; &omicron; &pi; &rho; &sigmaf; &sigma; &tau; &upsilon; &phi; &chi; &psi; &omega; &thetasym; &upsih; &piv; &ensp; &emsp; &thinsp; &zwnj; &zwj; &lrm; &rlm; &ndash; &mdash; &lsquo; &rsquo; &sbquo; &ldquo; &rdquo; &bdquo; &dagger; &Dagger; &bull; &hellip; &permil; &prime; &Prime; &lsaquo; &rsaquo; &oline; &frasl; &euro; &image; &weierp; &real; &trade; &alefsym; &larr; &uarr; &rarr; &darr; &harr; &crarr; &lArr; &uArr; &rArr; &dArr; &hArr; &forall; &part; &exist; &empty; &nabla; &isin; &notin; &ni; &prod; &sum; &minus; &lowast; &radic; &prop; &infin; &ang; &and; &or; &cap; &cup; &int; &there4; &sim; &cong; &asymp; &ne; &equiv; &le; &ge; &sub; &sup; &nsub; &sube; &supe; &oplus; &otimes; &perp; &sdot; &vellip; &lceil; &rceil; &lfloor; &rfloor; &lang; &rang; &loz; &spades; &clubs; &hearts; &diams; '; 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