my %capitals = (France => "Paris",
                Scotland => "Edinburgh",
                );
# find the capital "of" Scotland
print $capitals{"Scotland"}, "\n";

##</code><code>##

# we have a pre-prepared list of prime numbers
my @primeslist  =  qw(2 3 5 7 11 13 17 19 23 29);

# populate a hash with the primes as keys
# this allows for fast retrieval
my %primes;
@primes{@primeslist} = ();

# now we can loop through our new list ( 1 .. 30)
# using the exists() function to (quickly) check if a key exists
print "$_ is prime\n" for grep exists $primes{$_}, 1 .. 30;