#!/usr/bin/perl -w
use strict;

use Benchmark qw( cmpthese );

my $string = "1234567890";
my $new;

cmpthese( 0,
    {
        "reverse"  => sub { $new = scalar reverse( sprintf "%012s", scalar reverse( $string ) ) },
#        "regex"    => sub { $new = sprintf( "%-12d", $string ) =~ s/ /0/gr },
        "regexOld" => sub { ( $new = sprintf( qq( %-12d ), $string ) ) =~ s/ /0/g },
        "length"   => sub { $new = $string . 0 x ( 12 - length( $string ) ) },
        "mult"     => sub { $new = $string * 10 ** ( 12 - length( $string ) )  },
    }
);