数组-如何动态取消对数组的引用？ （Perl）

Question

When I do:

my (@array1, @array2) = get_returns();

The get_return function returns a list of arbitrary elements. In this particular case, the get_returns function returns a list of two arrays. However this stores all the contents of the return into array1 instead of splitting the two arrays up.

I am not sure how to dereference the arrays through the function I am calling using something explicit like @{$arr} . I am doing a form of RPC calling where the returns (and their types) are not known beforehand by the program. I also do not want to have to dereference the array outside of the function call. Is there a workaround to dynamically dereference the arrays?

Update

In the get_returns function, I am sending and receiving a response from a server. This returns a JSON table where the "returns" field is an array of returns:

sub get_returns {
    my $data = remotely_call_some_function();
    $t = $json->decode($data);
    my @returns = @{$t->{"returns"}};
    return @returns;
}

Answer 1

the get_returns function returns a list of two arrays.

No, it returns a number of scalars. That's the only thing a sub can return. In this specific case, it returns two references to arrays. You could grab them as follows:

my ($array1, $array2) = get_returns();

---

I also do not want to have to dereference the array outside of the function

To do that, you'd need named arrays outside of get_returns for get_returns to populate.

sub get_returns {
    my $data_json = remotely_call_some_function();
    my $data = $json->decode($data_json);
    my $returns = $data->{returns};
    @{ $_[0] } = $returns->[0];
    @{ $_[1] } = $returns->[1];
}

get_returns(\my @array1, \my @array2);

I recommend against this.

Answer 2

Per a comment that includes Data::Dumper output in the OP, you're receiving $VAR1 = [['e1', 'e2'], ['e1', 'e2']] . That's an array of array references. Here's how you can receive and then dereference the inner arefs:

my ($aref1, $aref2) = get_returns();

# deref and print each element of an array reference

for my $elem (@$aref1){
    print "$elem\n";
}

# get a single element

my $x = $aref2->[0];