use strict;
use Benchmark qw[cmpthese];

my @array = (1..100);

cmpthese(1000000, {
    'scalar' => \&last_index_scalar,
    'index'  => \&last_index,
    'context'=> \&last_index_context
});

sub last_index_context { my $val1 = @array-1; }
sub last_index   { my $val2 = $#array; }
sub last_index_scalar  { my $val3 = scalar(@array)-1; }

__DATA__
P:\test>test
            Rate  scalar context   index
scalar  207641/s      --     -4%    -17%
context 217014/s      5%      --    -14%
index   251509/s     21%     16%      --