perl 引用

数组的数组

 $a = [
     [1, 2, 3],
     [4, 5, 6],
     [7, 8, 9]
 ]

哈希的哈希

 my $student_properties_of = {
     'zdd' => {
         'age' => 30,
         'hight' => 170,
         'id' => '',
     },

     'autumn' => {
         'age' => 27,
         'hight' => 165,
         'id' => '',
     }
 } ;