cmpthese -3,{a=>q[@a = map $_*1, @a],b=>q[map $_*=1, @a],c=>q[$_*=1 for @a] };;

##</code><code>##

timethese (10000000,{a=>q{map {1} @a},b=>q[map $_*=1, @a],c=>q[$_*=1 for @a] });

##</code><code>##

#! perl -slw
use strict;
use Benchmark qw[ cmpthese ];

our @a = 1 .. 1e6;

cmpthese -1, {
    a => q[ @a = map $_*  1, @a ],
    b => q[      map $_*= 1, @a     ],
    c => q[          $_*= 1 for @a      ],
};

__END__
C:\test>BuksBench.pl
    Rate    a    c    b
a 3.46/s   -- -68% -68%
c 10.7/s 208%   --  -2%
b 10.8/s 213%   2%   --

##</code><code>##

timethese 10000, {
    "idiomatic" => sub { my @array = 1..1000;      $_ +=2 for @array; },
    "map"       => sub { my @array = 1..1000; map{ $_ +=2;}   @array; },
};

__END__
C:\test>IdiotsBench.pl
Benchmark: timing 10000 iterations of idiomatic, map...
 idiomatic:  2 wallclock secs ( 1.52 usr +  0.00 sys =  1.52 CPU) @ 6596.31/s (n=10000)
       map:  3 wallclock secs ( 3.06 usr +  0.00 sys =  3.06 CPU) @ 3264.77/s (n=10000)

##</code><code>##

C:\test>IdiotsBench.pl
my @array = 1..1000;
timethese 10000, {
    "idiomatic" => sub {      $_ +=2 for @array; },
    "map"       => sub { map{ $_ +=2 }   @array; },
};

__END__
C:\test>IdiotsBench.pl
Benchmark: timing 10000 iterations of idiomatic, map...
 idiomatic:  1 wallclock secs ( 0.92 usr +  0.00 sys =  0.92 CPU) @ 10845.99/s (n=10000)
       map:  2 wallclock secs ( 2.44 usr +  0.00 sys =  2.44 CPU) @ 4101.72/s (n=10000)

##</code><code>##

C:\test>IdiotsBench.pl
timethese 10000, {
    "idiomatic" => sub {     $_ +=2 for @array; },
    "map"       => sub { map $_ +=2,    @array; },
};

__END__
Benchmark: timing 10000 iterations of idiomatic, map...
 idiomatic:  1 wallclock secs ( 0.95 usr +  0.00 sys =  0.95 CPU) @ 10493.18/s (n=10000)
       map:  1 wallclock secs ( 0.95 usr +  0.00 sys =  0.95 CPU) @ 10493.18/s (n=10000)

##</code><code>##

our @array2 = 1 .. 1000;
timethese 10000, {
    "idiomatic" => q[     $_ +=2 for @array2; ],
    "map"       => q[ map $_ +=2,    @array2; ],
};

__END__
Benchmark: timing 10000 iterations of idiomatic, map...
 idiomatic:  1 wallclock secs ( 0.88 usr +  0.00 sys =  0.88 CPU) @ 11428.57/s (n=10000)
       map:  1 wallclock secs ( 0.84 usr +  0.00 sys =  0.84 CPU) @ 11848.34/s (n=10000)