perl的数据结构有关问题

perl的数据结构问题
最近看到一段程序，不知是属于何类型？

Perl code

my $category;$category -> {'apple'}  = "1";$category -> {'banana'} = "2";$category -> {'peach'}  = "3";

Perl code

#!/usr/bin/env perlmy $category;$category -> {'apple'}  = "1";$category -> {'banana'} = "2";$category -> {'peach'}  = "3";for $k (keys %{$category}) {    print "$k => $category->{$k}\n";}
[解决办法]
Perl code
#!/usr/bin/env perlmy $category;$category -> {'apple'}  = "1";$category -> {'banana'} = "2";$category -> {'peach'}  = "3";while (($k, $v) = each %{$category}) {    print "$k => $v\n";}