title: How do I add multiple elements to an array?
body: <p>I can easily add one element to an existing array:</p>
  
  <pre><code>arr = [1]
  arr &lt;&lt; 2
  # =&gt; [1, 2]
  </code></pre>
  
  <p>How would I add <strong>multiple</strong> elements to my array?</p>
  
  <p>I'd like to do something like <code>arr &lt;&lt; [2, 3]</code>, but this adds an array to my array <code>#=&gt; [1, [2, 3]]</code></p>