note
Athanasius
<p>Hello [stewart_lee], and welcome to the Monastery!</p>
<blockquote>
<i>I use 'use', then I should call the sub with ($$@@) instead of ($$\@\@)</i>
</blockquote>
<p>I think you may be confused about how prototypes work in Perl. Specifically, <tt>($$\@\@)</tt> means the subroutine expects:</p>
<ul>
<li>a scalar</li>
<li>another scalar</li>
<li>an array (<i>not</i> an array reference!)</li>
<li>another array</li>
</ul>
<p>The backslash in the prototype — <tt>\@</tt> — means the array will be <i>converted into</i> an array reference inside the sub. So, in your example,</p>
<code>
Money::Finance::getMovingAve(5,$size,@values,@mv);
...
sub getMovingAve($$\@\@) {
my ($count, $number, $values, $movingAve) = @_;
...
</code>
<p>the variables <tt>$values</tt> and <tt>$movingAve</tt> are assigned references to the arrays <tt>@values</tt> and <tt>@mv</tt>, respectively, <i>by virtue of the subroutine’s prototype</i>.</p>
<p>So, with [doc://use], the code is behaving as expected. But with [doc://require], the prototype is ignored because it is seen too late, so to make the sub work correctly you have to pass references explicitly.</p>
<p>Perl prototypes are confusing, and should probably be avoided unless you have a good reason to use them. Make sure to read [id://861966].</p>
<p>By the way, you would probably have received help sooner had you posted a trimmed-down (but still working) version of the code showing only the relevant parts. See [id://174051]</p>
<p>And <i>do not</i> comment out <tt>use strict;</tt> — it’s there to make your life easier!</p>
<p>Hope that helps,</p>
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<p>Athanasius <font color=#008000><°(((><</font> <i>contra mundum</i></p>
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