#!/usr/bin/perl -w

use 5.006;

use strict;
use Benchmark qw/ cmpthese /;

use vars qw/ @a @b /;

@a = ('a'..'z');

cmpthese(-3, {
   '1' => '@b = map uc,@a',
   '2' => '@b = map uc $_,@a',
   '3' => '@b = map uc(),@a',
   '4' => '@b = map uc($_),@a',
   '5' => '@b = map {uc} @a',
   '6' => '@b = map {uc $_} @a',
   '7' => '@b = map {uc()} @a',
   '8' => '@b = map {uc($_)} @a',
});

__END__

Benchmark: running 1, 2, 3, 4, 5, 6, 7, 8, each for at least 3 CPU seconds...
         1:  4 wallclock secs ( 3.17 usr +  0.01 sys =  3.18 CPU) @ 9706.92/s (n=30868)
         2:  4 wallclock secs ( 3.18 usr +  0.02 sys =  3.20 CPU) @ 9710.31/s (n=31073)
         3:  4 wallclock secs ( 3.13 usr +  0.02 sys =  3.15 CPU) @ 9773.02/s (n=30785)
         4:  4 wallclock secs ( 3.13 usr +  0.01 sys =  3.14 CPU) @ 9898.09/s (n=31080)
         5:  3 wallclock secs ( 3.17 usr +  0.00 sys =  3.17 CPU) @ 9611.67/s (n=30469)
         6:  3 wallclock secs ( 3.18 usr +  0.01 sys =  3.19 CPU) @ 9650.47/s (n=30785)
         7:  4 wallclock secs ( 3.04 usr +  0.02 sys =  3.06 CPU) @ 9582.68/s (n=29323)
         8:  4 wallclock secs ( 3.32 usr +  0.01 sys =  3.33 CPU) @ 9533.33/s (n=31746)
    Rate   8   7   5   6   1   2   3   4
8 9533/s  -- -1% -1% -1% -2% -2% -2% -4%
7 9583/s  1%  -- -0% -1% -1% -1% -2% -3%
5 9612/s  1%  0%  -- -0% -1% -1% -2% -3%
6 9650/s  1%  1%  0%  -- -1% -1% -1% -3%
1 9707/s  2%  1%  1%  1%  -- -0% -1% -2%
2 9710/s  2%  1%  1%  1%  0%  -- -1% -2%
3 9773/s  3%  2%  2%  1%  1%  1%  -- -1%
4 9898/s  4%  3%  3%  3%  2%  2%  1%  --