#!/usr/bin/perl
use strict;
use warnings;
use Benchmark qw( cmpthese );

my @data = split /\n/, <<END;
800-800-1212
(800)800-1212
(800) 800-1212
800 800 1212
END
 
sub dosloop {
        my $re = shift;
        (my $phone = $_) =~ s/$re//g foreach @data;
}
 
sub doyloop {
        my $fake = shift;
        (my $phone = $_) =~ y/0-9//cd foreach @data;
}
 
cmpthese(-10, {
                single => sub { dosloop(qr/\D/) },
                multiple=> sub { dosloop(qr/\D+/) },
                y => sub { doyloop(qr/\D/) },  # Just a fake parameter
        }
);