title: Assignment with double ampersand "&&"
body: <p>I just saw someone use this piece of code:</p>
  
  <pre><code>ctx = canvas.getContext &amp;&amp; canvas.getContext('2d');
  </code></pre>
  
  <p>How does the double ampersand work in this context? Would it not just assign "true" to the ctx variable?</p>