my @array     = qw( a b );
my $scalar    = 'xyz';
my $reference = \@array;

for (@array     ) { print("$_\n"); }  print("\n");
for ($scalar    ) { print("$_\n"); }  print("\n");
for ($reference ) { print("$_\n"); }  print("\n");
for (@$reference) { print("$_\n"); }  print("\n");