what does << do in javascript
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/141525/absolute-beginners-guide-to-bit-shifting">Absolute Beginner&#39;s Guide to Bit Shifting?</a><br>
  <a href="http://stackoverflow.com/questions/1822350/what-is-the-javascript-operator-and-how-do-you-use-it">What is the JavaScript &gt;&gt;&gt; operator and how do you use it?</a>  </p>
</blockquote>



<p>I came across <code>&lt;&lt;</code> while reading some code.</p>

<pre><code>1&lt;&lt;1 //2
2&lt;&lt;1 //4
3&lt;&lt;1 //6
3&lt;&lt;2 //12 
</code></pre>

<p><li>What is this called?</li>
<li>What does this do?</li></p>
