in reply to Using an array in a hash

Instead of directly answering your question (which other people have already done, well) I'll give you a few quick pointers on perl references (which other people will probably also do). First, you might want to take a look at perlref, (i.e. type perldoc perlref), it contains a pretty good explanation of how to use references in perl.

Basically, references are scalars, if you have a C background, just think of them as pointers, the only difference being that you can't do pointer arithmetic on them. (i.e. no $myref++; or similar).

Also, since perl is not a strongly typed language, you are responsible for keeping track of what data type a reference points to. There's no such thing as an 'array reference' or a 'hash reference', just a reference, which can point to either an array or a hash.

Some examples of referencing and dereferencing

# create a 'real' array and a reference to it. my @array = (1, 2, 3, 4); my $reftoactualarray = \@array; # create a reference to an anonymous array my $reftoanonymousarray = [1, 2, 3, 4]; # both print the same thing print @$reftoactualarray; print @$reftoanonymousarray;
The difference between a 'real' array and an anonymous one is that when you modify the array referenced by $reftoactualarray, the contents of @array actually change. If you change the array referenced by $reftoanonymousarray, nobody else will see the changes you made. Dereferencing arrays of hashes or hashes of arrays, or any complex data structure like that, can get pretty hairy.

Good Luck,

Corrections welcome.