roboticus@sparky:~$ cat t.pl
#!/usr/bin/perl
use strict;
use warnings;

my @foo = (5, 7, 9, 11, 13);

print $foo[scalar @foo - 1], "\n";
print $foo[@foo - 1], "\n";
print $foo[$#foo], "\n";
print $foo[-1], "\n";
print $foo[-2], "\n";
print $foo[-3], "\n";


roboticus@sparky:~$ perl t.pl
13
13
13
13
11
9
roboticus@sparky:~$