<p> It is often a better design to
return a length zero array rather than a null reference to indicate that there
are no results (i.e., an empty list of results).
This way, no explicit check for null is needed by clients of the method.</p>

<p>On the other hand, using null to indicate
"there is no answer to this question" is probably appropriate.
For example, <code>File.listFiles()</code> returns an empty list
if given a directory containing no files, and returns null if the file
is not a directory.</p>

<p>
This rule is deprecated, use {rule:squid:S1168} instead.
</p>