use strict;
use Benchmark qw/ cmpthese timethese /;
use List::Util qw/ reduce /;

my @list = 1..10;

cmpthese(
  timethese(1000000, {
    'map_void'    => '&map_void',
    'for_loop'    => '&for_loop',
    'list_reduce' => '&list_reduce',
  }));
  
# printf "%d, %d, %d\n", map_void(), for_loop(), list_reduce();

sub map_void {
    my $result = 1;
    map {$result *= $_} @list;
    return $result;
}

sub for_loop {
    my $result = 1;
    $result *= $_ foreach @list;
    return $result;
}

sub list_reduce {
    return reduce { $a * $b } @list;
}

__END__

Benchmark: timing 1000000 iterations of for_loop, list_reduce, map_void...
  for_loop:  4 wallclock secs ( 5.43 usr +  0.00 sys =  5.43 CPU) @ 184229.92/s
(n=1000000)
list_reduce:  9 wallclock secs ( 8.46 usr +  0.00 sys =  8.46 CPU) @ 118175.37/s
 (n=1000000)
  map_void:  5 wallclock secs ( 4.52 usr +  0.00 sys =  4.52 CPU) @ 221385.88/s
(n=1000000)
                Rate list_reduce    for_loop    map_void
list_reduce 118175/s          --        -36%        -47%
for_loop    184230/s         56%          --        -17%
map_void    221386/s         87%         20%          --