typeof(data.frame) shows "list" in R : <p>Can someone clarify why <strong>typeof (data.frame)</strong> shows <strong>list</strong> in R?  In contrast, class gives expected type. E.g., demonstrate that using the built-in data.frame mtcars. </p>

<pre><code>&gt; typeof(mtcars)
[1] "list"
&gt; class(mtcars)
[1] "data.frame"
</code></pre>

<p>Any hints on how to use typeof versus class?</p>
