Question about dereferencing

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi,

I have a bit of Perl homework where we got a code sample. I can see what
the code sample is doing except for two little bits

There's a part that has $row->[$i] and a part that has @$row . What do
these two parts mean?

The code sample turns csv into fixed width so it reads each line of the
file into an array @rows. Then in a for loop

for $row (@rows) {

There's another for loop

for $row (@rows) {
~  for ($i = 0; $i < @$row; i++) {
~    $w = length $row->[$i]
~    ...

I'm assuming that the $row is itself another array or can be treated as
one and @$row can give you a number of the elements in it and $row->[$i]
is some sort of deferencing mechanism. The perlop page seemed a bit
cryptic to me as to what the arrow operator does exactly and I could
search for the use of @ in that context.

Any assistance would be appreciated.

Thanks
Christopher
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFITqKkHMIyvsjgzMQRArxvAJ439TwCoUMQwILEPRPWj8X2tkiArQCgkhbf
7HgDgbPgLQIA1jv7N9R2zDI=
=gxOg
-----END PGP SIGNATURE-----