How do I refer to an element of a hash of arrays as an array

[Anonymous Monk]

I create a hash where each element refers to an array:

$h{'one'} = [1,2,3];

I can access the individual array elements o.k.:

print "$h{'one'}[1]\n";

prints "2" as I expect.

Why can't I access the entire array as if it were a regular array?
What don't I understand here:

my @a = $h{'one'};
print "$a[1]\n";

doesn't do what I expect.

Originally posted as a Categorized Question.

[arturo]

Since hash values can only be scalars, the value is a reference to an array. That is, it's like a pointer. (Try print "$h{'one'}\n" and see what you get.)

To get at the thing the reference points to, you need to explicitly dereference it. To get at the array, do

my @a = @{ $h{one} };

By enclosing something in the @{ } construction, you're saying that you want the array to which that reference points.

[arhuman]

beccause $h{'one'} is a ref to an array !
Use my @a=@$h{'one'};

Originally posted as a Categorized Answer.

[lachoy]

Also, just for future debugging purposes, you might want to print out more than the second element of the array. Doing something like:

 my @a=$h{'one'};
 print join( ' // ', @a );

might have shown you something like:

ARRAY(0x80e1310)

which would hopefully be a giant red flag :-)

Originally posted as a Categorized Answer.