Primitive value vs Reference value
<p>I read a book called "Professional Javascript for web developer" and it says: "Variable is assigned by Reference value or Primitive Value. Reference values are objects stored in memory". And then it says nothing about how Primitive value is stored. So I guess it isn't stored in memory. Based on that, when I have a script like this:</p>

<pre><code>var foo = 123;
</code></pre>

<p>How does Javascript remember the <code>foo</code> variable for later use?</p>
