note
Athanasius
<p>This is a nicely-written program, well done! If the C++ version is up to this standard, you should get high marks on the assignment.</p>
<p>I did notice one logical error:</p>
<code>
print "Division by zero not allowed, starting over..." and redo
if ( $frac01 =~ /^[\s\S]?\/?0$/ );
</code>
<p>If the user enters <tt>1/0</tt>, this correctly flags division by zero. But,</p>
<ul>
<li>If the user enters <tt>12/0</tt>, the regex fails and division by zero is not caught.</li>
<li>If the user enters <tt>10</tt>, the regex matches and gives a false positive.</li>
</ul>
<p>How to fix this? One way would be to extract the denominator (if any) and test whether that is zero. But this is Perl, so TMTOWTDI.</p>
<p>Now to style: In Perl, it’s better to declare a variable as late as possible in the code. So, looking at this line:</p>
<code>
my ( $f1, $f2, $frac01, $frac02, $command, $total ) = (0) x 6;
</code>
<p>actually only <tt>$command</tt> needs to be declared before the outer <tt>while</tt> loop. The rest can safely be declared at the point of first use. (And yes, I would declare <tt>$total</tt> separately within each of the <tt>if / elsif</tt> blocks.)</p>
<p>Hope that helps,</p>
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Athanasius <font color="#008000"><</font>[href://http://www.biblegateway.com/passage/?search=John%203:16&version=NLV|<font color="#008000">°</font>]<font color="#008000">(((><</font> <i>contra mundum</i>
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