Let's try:

my $switchnum = 15;
my $calltype = []; # Empty array ref
print "ref of switchnum = ref($switchnum) \n
       ref of calltype = ref($calltype) \n";
[download]

It prints:

ref of switchnum = ref(15) 

       ref of calltype = ref(ARRAY(0x1234567))
[download]

Guess what: you can't interpolate functions that way :)

Try this one:

ref(eval "\$$_") or warn "\$$_ is not a reference" for qw(switchnum ca
+lltype);
[download]

++ vs lbh qrpbqrq guvf hfvat n ge va Crey :)
Nabgure bar vs lbh qvq fb jvgubhg ernqvat n znahny svefg.
-- vs lbh hfrq OFQ pnrfne ;)
    - Whreq