title: How can I create a multi-dimensional array in perl?
body: <p>I was creating a multi-dimensional array this way:</p>
  <pre><code>#!/usr/bin/perl
  use warnings;
  use strict;
  
  my @a1 = (1, 2);
  my @a2 = (@a1, 3);
  </code></pre>
  <p>But it turns out that I still got a one-dimensional array...</p>
  <p>What's the right way in Perl?</p>