...and my old friend 'grep'
Not quite as fast as btrott but still a decent contender.
use Benchmark;
my @array = qw(a b c d e f g h i j k l m n o p q r s t u v w z y z);
my %hash;
timethese(
500000,
{
'btrott' => sub {
@hash{@array} = (1) x @array;
},
'httptech' => sub {
for (@array) { $hash{$_} = 1 }
},
'danimal' => sub {
grep { $hash{$_}++ } @array;
}
},
);
Benchmark: timing 500000 iterations of btrott, danimal, httptech...
btrott: 21 wallclock secs (21.38 usr + 0.00 sys = 21.38 CPU)
danimal: 22 wallclock secs (22.57 usr + 0.00 sys = 22.57 CPU)
httptech: 34 wallclock secs (34.10 usr + 0.00 sys = 34.10 CPU)