use Benchmark 'cmpthese';
my @a = map {"$_\n"} 1..1000000;
cmpthese(100, {
    forloop => sub {
        open FILE, ">file.out" or die "Can't open file: $!\n";
        print FILE $_ for @a;
        close FILE;
        },
    array   => sub {
        open FILE, ">file.out" or die "Can't open file: $!\n";
        print FILE @a;
        close FILE;
        }
});

##</code><code>##

Benchmark: timing 100 iterations of array, forloop...
     array: 28 wallclock secs (22.62 usr +  2.74 sys = 25.36 CPU) @  3.94/s (n=100)
   forloop: 69 wallclock secs (61.52 usr +  2.75 sys = 64.27 CPU) @  1.56/s (n=100)
          Rate forloop   array
forloop 1.56/s      --    -61%
array   3.94/s    153%      --