Assignment to not yet defined array index
<pre><code>$mailSent = mail($to, $subject, $message, $headers);
if (!$mailSent) {
   $errors['mailfail'] = true;
}
</code></pre>

<p>I'm confused by this line:</p>

<pre><code>$errors['mailfail'] = true;
</code></pre>

<p><code>$errors</code> is an empty array, so basically the index <code>mailfail</code> doesn't exist. Right?</p>
