title: How do I print a hash structure in Perl?
body: <p>Examples:</p>
  
  <pre><code>%hash = (2010 =&gt; 21, 2009=&gt; 9);
  
  $hash = {
      a =&gt; {
          0 =&gt; {test =&gt; 1},
          1 =&gt; {test =&gt; 2},
          2 =&gt; {test =&gt; 3},
          3 =&gt; {test =&gt; 4},
      },
  };
  </code></pre>
  
  <p>How do I print the hash?</p>