in reply to Strip non-numeric

Sure, you can use a substitution:   s/\D//g; # global or you can use a special transliteration:   tr/0-9//cd; # complement, delete A more elaborate description is found in the perlop document.

I must here point out that s/// and tr/// are two totally different operators! As said, they're documented in perlop.

Other documents you might want to read are the perlre* documents. All perldocs are listed in the document "perl" (perldoc perl).

Hope I've helped,
ihb

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Re: Strip non-numeric
by FireBird34 (Pilgrim) on Jan 13, 2003 at 22:58 UTC
    Thanks all -- got it :-) I ended up using: 
    $scalar = "a1b2";
$scalar =~ s/\D//g;
print $scalar;

    [download]
    Also, I'll take a look at the perl documents on the s/// tr/// differences. Thanks.
[reply]
[d/l]
      You should consider using s/\D+//g, as that's often a lot faster than s/\D//g. Here's a benchmark: 
      #!/usr/bin/perl

use strict;
use warnings;

use Benchmark;

my @sizes = (10, 25, 50, 100, 250, 500, 1000);
my @chars = ('A' .. 'Z', 'a' .. 'z', 0 .. 9);

our @d = map {join "" => map {$chars [rand @chars]} 1 .. $_} @sizes;

map {
    Benchmark::cmpthese timethese (-2 => {
        "simple_$sizes[$_]"   => '$_ = $::d[' . $_ . ']; s/\D//g;',
        "multiple_$sizes[$_]" => '$_ = $::d[' . $_ . ']; s/\D+//g;'
    }, 'none');
} 0 .. $#sizes
__END__
                Rate   simple_10 multiple_10
simple_10   196495/s          --        -15%
multiple_10 231225/s         18%          --
                Rate   simple_25 multiple_25
simple_25    89788/s          --        -50%
multiple_25 180650/s        101%          --
                Rate   simple_50 multiple_50
simple_50    47507/s          --        -64%
multiple_50 130727/s        175%          --
                 Rate   simple_100 multiple_100
simple_100    23206/s           --         -77%
multiple_100 103096/s         344%           --
                Rate   simple_250 multiple_250
simple_250   10488/s           --         -71%
multiple_250 36407/s         247%           --
                Rate   simple_500 multiple_500
simple_500    5046/s           --         -75%
multiple_500 20382/s         304%           --
                 Rate   simple_1000 multiple_1000
simple_1000    2528/s            --          -76%
multiple_1000 10549/s          317%            --

      [download]

      Abigail

[reply]
[d/l]
[select]
        In this case transliteration is really the most efficient solution though. Consider the results of adding         "xlit_$sizes[$_]"     => '$_ = $::d[' . $_ . ']; tr/0-9//cd;', to the benchmark: 
                        Rate   simple_10 multiple_10     xlit_10
simple_10    86400/s          --        -31%        -70%
multiple_10 124615/s         44%          --        -57%
xlit_10     292712/s        239%        135%          --
                Rate   simple_25 multiple_25     xlit_25
simple_25    45324/s          --        -49%        -82%
multiple_25  88062/s         94%          --        -65%
xlit_25     248802/s        449%        183%          --
                Rate   simple_50 multiple_50     xlit_50
simple_50    23823/s          --        -71%        -89%
multiple_50  82566/s        247%          --        -62%
xlit_50     218684/s        818%        165%          --
                 Rate   simple_100 multiple_100     xlit_100
simple_100    13397/s           --         -69%         -92%
multiple_100  43191/s         222%           --         -74%
xlit_100     168434/s        1157%         290%           --
                 Rate   simple_250 multiple_250     xlit_250
simple_250     5608/s           --         -71%         -95%
multiple_250  19639/s         250%           --         -81%
xlit_250     103656/s        1748%         428%           --
                Rate   simple_500 multiple_500     xlit_500
simple_500    2832/s           --         -72%         -95%
multiple_500 10189/s         260%           --         -83%
xlit_500     59072/s        1986%         480%           --
                 Rate   simple_1000 multiple_1000     xlit_1000
simple_1000    1380/s            --          -77%          -96%
multiple_1000  5939/s          330%            --          -83%
xlit_1000     34457/s         2397%          480%            --

        [download]
        Esp in large data sets, transliteration screams.

        Makeshifts last the longest.

[reply]
[d/l]
[select]
        Ok, thanks. Also did have one more question about this -- I didn't take into consideration about valid non-numeric (only decmial). So for example, 1a2b3.4c5d6e, I would want 123.456, not just 123456 -- tried a few combinations, but nothing yet. I'm missing something obvious I know ;) Any pointers?
[reply]
        Basically, in any given string, I want only numeric and decimal values retained. So, basically:

        1a => 1
        1a.2b => 1.2
        1a.2b.3c => 1.2.3

        ^^ Just as those show, no matter how many decimals or numeric values, those are the only characters I want retained. Hope this clears it up just a bit.
[reply]

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