map { $code .= "\$hash{$_} = 1;\n" } @array; eval "$code"; #### 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(10000, { 'btrott' => sub { @hash{@array} = (1) x @array; }, 'plaid' => sub { my $code map { $code .= "\$hash{$_} = 1;\n" } @array; eval "$code"; } }); #### Benchmark: timing 10000 iterations of btrott, plaid... btrott: 1 wallclock secs ( 0.56 usr + 0.00 sys = 0.56 CPU) plaid: 23 wallclock secs (22.07 usr + 0.06 sys = 22.13 CPU)