title: How can I combine hashes in Perl?
body: <p>What is the best way to combine both hashes into %hash1?  I always know that %hash2 and %hash1 always have unique keys.  I would also prefer a single line of code if possible.  </p>
  
  <pre><code>$hash1{'1'} = 'red';
  $hash1{'2'} = 'blue';
  $hash2{'3'} = 'green';
  $hash2{'4'} = 'yellow';
  </code></pre>