What does 0x0F mean? And what does this code mean?
<p>I have this code. Please make me understand what does this code actually mean</p>

<pre><code>  for(var i = 0; i &lt; input.length; i++)
  {
    x = input.charCodeAt(i);
    output += hex_tab.charAt((x &gt;&gt;&gt; 4) &amp; 0x0F)
           +  hex_tab.charAt( x        &amp; 0x0F);
  }
</code></pre>

<p>What is 0x0F? And, >>> Mean?</p>
