#!/usr/bin/perl
use strict;
use warnings;
$| =1;  #turn off STDIO buffering
        #this causes the error messages to STDERR
        #to appear closer to the standard print stuff

my @numbers = qw(1 -1 123.1 0.1 1E6  );

foreach my $number (@numbers)
{
   print "$number:  \t", $number+0,"\n";
}

print "now weirder stuff...\n\n";

@numbers = qw (1.1.1 4-1-1 --2);

foreach my $number (@numbers)
{
   print "$number:  \t", $number+0,"\n";
}

__END__
OUTPUT: 

1:      1
-1:     -1
123.1:      123.1
0.1:    0.1
1E6:    1000000
now weirder stuff...

Argument "1.1.1" isn't numeric in addition (+) at C:\PerlTemp\testnumeric2.pl line 19.
1.1.1:      1.1
Argument "4-1-1" isn't numeric in addition (+) at C:\PerlTemp\testnumeric2.pl line 19.
4-1-1:      4
Argument "--2" isn't numeric in addition (+) at C:\PerlTemp\testnumeric2.pl line 19.
--2:    0