What's wrong with:

$length = @array;
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For example:

#!/usr/bin/perl

use strict;

my @array = qw(one two three);

my $length = $#array + 1;
print "Dollar pound array = $length\n";
$length = @array;
print "At symbol array = $length\n";

__DATA__
{C} > test.pl
Dollar pound array = 3
At symbol array = 3
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