##
print ${ $hash_ref{ $key } };
####
sub x{ print $$_[0][1] };;
####
x( [['a','b'],['c','d']] );;
x( ['a','b'],['c','d'] );;
####
x( [['a','b'],['c','d']] );;
Use of uninitialized value in print at ...
x( ['a','b'],['c','d'] );;
Use of uninitialized value in print at ...
####
sub x{ print $_[0]->[1] };;
xx( [['a','b'],['c','d']] );;
xx( ['a','b'],['c','d'] );;
####
x( [['a','b'],['c','d']] );;
ARRAY(0x3c6e3b8)
x( ['a','b'],['c','d'] );;
b