Why is this program valid?
<p>Reading <a href="http://stackoverflow.com/questions/11695110/why-is-this-program-valid-i-was-trying-to-create-a-syntax-error">this fascinating question</a> made me remember a code snippet I stumbled across a few weeks ago; it gave me quite a few minutes of confusion until I figured out why it works, maybe it will be interesting for others as well.</p>

<pre><code>&lt;?php

http://example.com/some-article
$items = get_items();
// etc.
</code></pre>

<p>Obviously the programmer wanted to add an explanatory link as a comment before the code block, but forgot to add the <code>//</code> to the beginning. Nevertheless, the code works fine. Can you tell why?</p>
