but entire arrays or array slices are denoted by '@',
       which works much like the word "these" or "those":

           @days               # ($days[0], $days[1],... $days[n])
           @days[3,4,5]        # same as @days[3..5]
           @days{'a','c'}      # same as ($days{'a'},$days{'c'})

       and entire hashes are denoted by '%':

           %days               # (key1, val1, key2, val2 ...)