Regular Expressions 101

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Function

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  • Substitution
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  • Unit Tests (36)
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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
Processing...

Test String

Code Generator

Language

Generated Code

$re = '/^(?=(?>[^{}()<>]*\[+[^{}()<>]*\]+[^{}()<>]*)*$|(?>[^[\]()<>]*\{+[^[\]()<>]*\}+[^[\]()<>]*)*$|(?>[^[\]{}<>]*\(+[^[\]{}<>]*\)+[^[\]{}<>]*)*$|(?>[^[\]{}()]*\<+[^[\]{}()]*\>+[^[\]{}()]*)*$|(?>[^[\]{}()<>]*)*$)(?=(?>[^"]*\“+[^"]*\”+[^"]*)*$|(?>[^“”]*\"+[^“”]*\"+[^“”]*)*$|(?>[^"“”]*)*$)(?=(?>[^\']*‘+[^\']*’+[^\']*)*$|(?>[^‘’]*\'+[^‘’]*\'+[^‘’]*)*$|(?>[^\'‘’]*)*$)[A-Za-z0-9 \"“”\'‘’()[\]{}<>«»\\\\\/?!&@£$€¥.,-]{3}[A-Za-z0-9 \"“”\'‘’()[\]{}<>«»\\\\\/?!&@£$€¥.,\-*=#%+]{0,157}$/'; $str = '/^ (?= (?> [^{}()<>]* \\[+ [^{}()<>]* \\]+ [^{}()<>]* ) *$| (?> [^[\\]()<>]* \\{+ [^[\\]()<>]* \\}+ [^[\\]()<>]* ) *$| (?> [^[\\]{}<>]* \\(+ [^[\\]{}<>]* \\)+ [^[\\]{}<>]* ) *$| (?> [^[\\]{}()]* \\<+ [^[\\]{}()]* \\>+ [^[\\]{}()]* ) *$| (?> [^[\\]{}()<>]* ) *$ ) (?= (?> [^"]* \\“+ [^"]* \\”+ [^"]* ) *$| (?> [^“”]* \\"+ [^“”]* \\"+ [^“”]* ) *$| (?> [^"“”]* ) *$ ) (?= (?> [^\']* ‘+ [^\']* ’+ [^\']* ) *$| (?> [^‘’]* \'+ [^‘’]* \'+ [^‘’]* ) *$| (?> [^\'‘’]* ) *$ ) [A-Za-z0-9 \\"“”\'‘’()[\\]{}<>«»\\\\\\/?!&@£$€¥.,-]{3} [A-Za-z0-9 \\"“”\'‘’()[\\]{}<>«»\\\\\\/?!&@£$€¥.,\\-*=#%+]{0,157} $/'; preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0); // Print the entire match result var_dump($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