Hi

To your first question: you can have multiple values per key by using an array reference as the value:

my (@keys, @values1, @values2);
my %hash;
for (0 .. $#keys) {
   $hash{$keys[$_]} = [ $values1[$_], $values2[$_] ];
}
[download]

A more compact method would use an hash slice and map:

@hash{ @keys } = map { [ $values1[$_], $values2[$_] ] } 0 .. $#values1
+;
[download]

Now, for a give key, here is how you can get the values:

# Return as an array:
@values = @{ $hash{ $key } };
print $values[0];

# Return as an array ref:
$values = $hash{ $key };
print $values->[0];
[download]

As for your second question: you can use a hash slice, again, to fetch a list of values based on a list of keys:

@values = @hash{ @keys };
for (@values) {
   print $_->[0], $_->[1];
}
[download]

A very important thing with this is watch the sigils (i.e. $, @, %) very closely.

More Information:

perldata has information about hashes and subscripts.

perlref has information about references and dereferencing.