Actually perl doesn't mid a bit if you have too many commas in a list, and in fact I've heard monks advocate a trailing comma to make it easier later to expand the list. I avoid doing it myself but mostly for aesthetic reasons.

use strict;
use warnings;

my @list = ('foo', 'bar',,,,'baz',,,,);
print "Item $_\n" for @list;
print "Length " . scalar @list."\n";
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Note that perl even gets the length of the array correct.