How to build LWP::UserAgent form parameters dynamically?

I want to build a set of form parameters for use in an HTTP POST on the fly, but I'm not sure how to access/build the data structure LWP::UserAgent uses dynamically.

The typical example code has this structure being passed as a request.

my $response = $browser->post(
  'http://example.com/postme',
  [
    'param1'  => 'value1',
    'param2' => 'value2'
  ],
);

I have a set of parameter names and values stored in a hash, and I want to build the structure in the square brackets from my hash data. What is that structure, and how can I do what I want to do? (as you can tell, I'm no perl expert!)

Solution

The square brackets construct an arrayref, but in this case the post method accepts either an arrayref or a hashref. So you can just do:

my %params;
$params{param1} = 'value1'; # store parameters into %params here
my $response = $browser->post('http://example.com/postme', \%params);

Read perlreftut for an introduction to references, and perlref for more details.