# phpman > perldoc > Regexp::Common::number

## NAME
    [Regexp::Common::number](https://www.chedong.com/phpMan.php/perldoc/Regexp%3A%3ACommon%3A%3Anumber/markdown) -- provide regexes for numbers

## SYNOPSIS
        use [Regexp::Common](https://www.chedong.com/phpMan.php/perldoc/Regexp%3A%3ACommon/markdown) qw /number/;

        while (<>) {
            /^$RE{num}{int}$/                and  print "Integer\n";
            /^$RE{num}{real}$/               and  print "Real\n";
            /^$RE{num}{real}{-base => 16}$/  and  print "Hexadecimal real\n";
        }

## DESCRIPTION
    Please consult the manual of [Regexp::Common](https://www.chedong.com/phpMan.php/perldoc/Regexp%3A%3ACommon/markdown) for a general description of the works of this
    interface.

    Do not use this module directly, but load it via *[Regexp::Common](https://www.chedong.com/phpMan.php/perldoc/Regexp%3A%3ACommon/markdown)*.

  $RE{num}{int}{-base}{-sep}{-group}{-places}{-sign}
    Returns a pattern that matches an integer.

    If "-base => *B*" is specified, the integer is in base *B*, with "2 <= *B* <= 36". For bases
    larger than 10, upper case letters are used. The default base is 10.

    If "-sep => *P*" is specified, the pattern *P* is required as a grouping marker within the
    number. If this option is not given, no grouping marker is used.

    If "-group => *N*" is specified, digits between grouping markers must be grouped in sequences of
    exactly *N* digits. The default value of *N* is 3. If "-group => *N,M*" is specified, digits
    between grouping markers must be grouped in sequences of at least *N* digits, and at most *M*
    digits. This option is ignored unless the "-sep" option is used.

    If "-places => *N*" is specified, the integer recognized must be exactly *N* digits wide. If
    "-places => *N,M*" is specified, the integer must be at least *N* wide, and at most *M*
    characters. There is no default, which means that integers are unlimited in size. This option is
    ignored if the "-sep" option is used.

    If "-sign => *P*" is used, it's a pattern the leading sign has to match. This defaults to
    "[-+]?", which means the number is optionally preceded by a minus or a plus. If you want to
    match unsigned integers, use $RE{num}{int}{-sign => ''}.

    For example:

     $RE{num}{int}                          # match 1234567
     $RE{num}{int}{-sep=>','}               # match 1,234,567
     $RE{num}{int}{-sep=>',?'}              # match 1234567 or 1,234,567
     $RE{num}{int}{-sep=>'.'}{-group=>4}    # match 1.2345.6789

    Under "-keep" (see [Regexp::Common](https://www.chedong.com/phpMan.php/perldoc/Regexp%3A%3ACommon/markdown)):

    $1  captures the entire number

    $2  captures the optional sign of the number

    $3  captures the complete set of digits

  $RE{num}{real}{-base}{-radix}{-places}{-sep}{-group}{-expon}
    Returns a pattern that matches a floating-point number.

    If "-base=*N*" is specified, the number is assumed to be in that base (with A..Z representing
    the digits for 11..36). By default, the base is 10.

    If "-radix=*P*" is specified, the pattern *P* is used as the radix point for the number (i.e.
    the "decimal point" in base 10). The default is "qr/[.]/".

    If "-places=*N*" is specified, the number is assumed to have exactly *N* places after the radix
    point. If "-places=*M,N*" is specified, the number is assumed to have between *M* and *N* places
    after the radix point. By default, the number of places is unrestricted.

    If "-sep=*P*" specified, the pattern *P* is required as a grouping marker within the pre-radix
    section of the number. By default, no separator is allowed.

    If "-group=*N*" is specified, digits between grouping separators must be grouped in sequences of
    exactly *N* characters. The default value of *N* is 3.

    If "-expon=*P*" is specified, the pattern *P* is used as the exponential marker. The default
    value of *P* is "qr/[Ee]/".

    If "-sign=*P*" is specified, the pattern *P* is used to match the leading sign (and the sign of
    the exponent). This defaults to "[-+]?", means means that an optional plus or minus sign can be
    used.

    For example:

     $RE{num}{real}                  # matches 123.456 or -0.1234567
     $RE{num}{real}{-places=>2}      # matches 123.45 or -0.12
     $RE{num}{real}{-places=>'0,3'}  # matches 123.456 or 0 or 9.8
     $RE{num}{real}{-sep=>'[,.]?'}   # matches 123,456 or 123.456
     $RE{num}{real}{-base=>3'}       # matches 121.102

    Under "-keep":

    $1  captures the entire match

    $2  captures the optional sign of the number

    $3  captures the complete mantissa

    $4  captures the whole number portion of the mantissa

    $5  captures the radix point

    $6  captures the fractional portion of the mantissa

    $7  captures the optional exponent marker

    $8  captures the entire exponent value

    $9  captures the optional sign of the exponent

    $10 captures the digits of the exponent

  $RE{num}{dec}{-radix}{-places}{-sep}{-group}{-expon}
    A synonym for $RE{num}{real}{-base=>10}{...}

  $RE{num}{oct}{-radix}{-places}{-sep}{-group}{-expon}
    A synonym for $RE{num}{real}{-base=>8}{...}

  $RE{num}{bin}{-radix}{-places}{-sep}{-group}{-expon}
    A synonym for $RE{num}{real}{-base=>2}{...}

  $RE{num}{hex}{-radix}{-places}{-sep}{-group}{-expon}
    A synonym for $RE{num}{real}{-base=>16}{...}

  $RE{num}{decimal}{-base}{-radix}{-places}{-sep}{-group}
    The same as $RE{num}{real}, except that an exponent isn't allowed. Hence, this returns a pattern
    matching *decimal* numbers.

    If "-base=*N*" is specified, the number is assumed to be in that base (with A..Z representing
    the digits for 11..36). By default, the base is 10.

    If "-radix=*P*" is specified, the pattern *P* is used as the radix point for the number (i.e.
    the "decimal point" in base 10). The default is "qr/[.]/".

    If "-places=*N*" is specified, the number is assumed to have exactly *N* places after the radix
    point. If "-places=*M,N*" is specified, the number is assumed to have between *M* and *N* places
    after the radix point. By default, the number of places is unrestricted.

    If "-sep=*P*" specified, the pattern *P* is required as a grouping marker within the pre-radix
    section of the number. By default, no separator is allowed.

    If "-group=*N*" is specified, digits between grouping separators must be grouped in sequences of
    exactly *N* characters. The default value of *N* is 3.

    For example:

     $RE{num}{decimal}                  # matches 123.456 or -0.1234567
     $RE{num}{decimal}{-places=>2}      # matches 123.45 or -0.12
     $RE{num}{decimal}{-places=>'0,3'}  # matches 123.456 or 0 or 9.8
     $RE{num}{decimal}{-sep=>'[,.]?'}   # matches 123,456 or 123.456
     $RE{num}{decimal}{-base=>3'}       # matches 121.102

    Under "-keep":

    $1  captures the entire match

    $2  captures the optional sign of the number

    $3  captures the complete mantissa

    $4  captures the whole number portion of the mantissa

    $5  captures the radix point

    $6  captures the fractional portion of the mantissa

  $RE{num}{square}
    Returns a pattern that matches a (decimal) square. Because Perl's arithmetic is lossy when using
    integers over about 53 bits, this pattern only recognizes numbers less than 9000000000000000, if
    one uses a Perl that is configured to use 64 bit integers. Otherwise, the limit is 2147483647.
    These restrictions were introduced in versions 2.116 and 2.117 of [Regexp::Common](https://www.chedong.com/phpMan.php/perldoc/Regexp%3A%3ACommon/markdown). Regardless
    whether "-keep" was set, the matched number will be returned in $1.

  $RE{num}{roman}
    Returns a pattern that matches an integer written in Roman numbers. Case doesn't matter. There
    is no unique way of writing Roman numerals, but we will not match anything. We require the Roman
    numerals to list the symbols in order (largest first). The symbols for thousand ("M"), hundred
    ("C"), ten ("X"), and one ("I") can not be repeated more than four times. The symbols for five
    hundred ("D"), fifty ("L"), and five ("V") may not appear more than once. A sequence of four
    repeated characters may also be written as a subtraction: by using the repeated character just
    once, and have it followed by the symbol which is 5 or 10 as large. So, four can be written as
    "IIII", or as "IV", and nine may be written as "VIIII" or "IX". This corresponds to most modern
    uses of Roman numerals.

    The largest number which will be matched is 4999, or "MMMMDCCCCLXXXXVIIII", or "MMMMCMXCIX".

    Under "-keep", the number will be captured in $1.

## SEE ALSO
    [Regexp::Common](https://www.chedong.com/phpMan.php/perldoc/Regexp%3A%3ACommon/markdown) for a general description of how to use this interface.

## AUTHOR
    Damian Conway (<damian@conway.org>)

## MAINTENANCE
    This package is maintained by Abigail (*<regexp-common@abigail.be>*).

## BUGS AND IRRITATIONS
    Bound to be plenty.

    For a start, there are many common regexes missing. Send them in to *<regexp-common@abigail.be>*.

LICENSE and COPYRIGHT
    This software is Copyright (c) 2001 - 2017, Damian Conway and Abigail.

    This module is free software, and maybe used under any of the following licenses:

     1) The Perl Artistic License.     See the file COPYRIGHT.AL.
     2) The Perl Artistic License 2.0. See the file COPYRIGHT.AL2.
     3) The BSD License.               See the file COPYRIGHT.BSD.
     4) The MIT License.               See the file COPYRIGHT.MIT.

