DB<1> print $results
HASH(0x8421888)

# So $results stores a reference to a hash

DB<2> print join ', ', keys %$results
string

# So the hash has a single key, 'string'

DB<3> print $results->{string}
ARRAY(0x8421438)

# So the hash stores a reference to an array as the value for its only key

DB<4>print $results->{string}[0]
# This part left as an exercise for the reader.