perl中哈希的哈希问题

我在访问散列中的变量时遇到问题，我不知道我做错了什么。在调试哈希%list1的值时，给出了一个undef，因此我无法获取我的值

use strict ;
use warnings ;
my $text = "The, big, fat, little, bastards";
my $Author = "Alex , Shuman ,Directory";
my %hashes  = {1,2,3,40};
my %count  = ();
my @lst = split(",",$text);
my $i = 0 ;
my @Authors  =  split(",", $Author);
foreach  my $SingleAuthor(@Authors)
{
    foreach my $dig (@lst)
    {

     $count{$SingleAuthor}{$dig}++;
    }
}

counter(\%count);

sub counter
{
    my $ref  =  shift;
    my @SingleAuthors = keys %$ref;
    my %list1;
    foreach  my $SingleAuthor1(@SingleAuthors)
  {   
   %list1 =  $ref->{$SingleAuthor1};
    foreach my $dig1 (keys %list1)
    {

     print  $ref->{$SingleAuthor1}->{$dig1};
    }
}


}

---

在两个地方，您试图将哈希引用分配给哈希，这会导致以下警告：在预期大小为偶数的列表中找到引用

以下是您需要进行的两次编辑：

# I changed {} to ().
# However, you never use %hashes, so I'm not sure why it's here at all.
my %hashes  = (1,2,3,40);

# I added %{} around the right-hand side.
%list1 =  %{$ref->{$SingleAuthor1}};

有关复杂数据结构的有用简要讨论，请参见

值得一提的是，通过删除中间变量，可以简化计数器方法而不损失可读性

sub counter {
    my $tallies = shift;
    foreach my $author (keys %$tallies) {   
        foreach my $dig (keys %{$tallies->{$author}}) {
            print $tallies->{$author}{$dig}, "\n";
        }
    }
}

或者，正如伊斯特所指出的，如果你不需要钥匙，就像这样：

    foreach my $author_digs (values %$tallies) {   
        print $dig, "\n" for values %$author_digs;
    }

---

在两个地方，您试图将哈希引用分配给哈希，这会导致以下警告：在预期大小为偶数的列表中找到引用

以下是您需要进行的两次编辑：

# I changed {} to ().
# However, you never use %hashes, so I'm not sure why it's here at all.
my %hashes  = (1,2,3,40);

# I added %{} around the right-hand side.
%list1 =  %{$ref->{$SingleAuthor1}};

有关复杂数据结构的有用简要讨论，请参见

值得一提的是，通过删除中间变量，可以简化计数器方法而不损失可读性

sub counter {
    my $tallies = shift;
    foreach my $author (keys %$tallies) {   
        foreach my $dig (keys %{$tallies->{$author}}) {
            print $tallies->{$author}{$dig}, "\n";
        }
    }
}

或者，正如伊斯特所指出的，如果你不需要钥匙，就像这样：

    foreach my $author_digs (values %$tallies) {   
        print $dig, "\n" for values %$author_digs;
    }

---

当我运行您的代码时，Perl准确地告诉了我问题所在

$ ./hash
Reference found where even-sized list expected at ./hash line 7.
Reference found where even-sized list expected at ./hash line 30.
Use of uninitialized value in print at ./hash line 34.
Reference found where even-sized list expected at ./hash line 30.
Use of uninitialized value in print at ./hash line 34.
Reference found where even-sized list expected at ./hash line 30.
Use of uninitialized value in print at ./hash line 34.

如果不清楚，您可以打开诊断以获得更详细的描述

$ perl -Mdiagnostics hash
Reference found where even-sized list expected at hash line 7 (#1)
    (W misc) You gave a single reference where Perl was expecting a list
    with an even number of elements (for assignment to a hash). This usually
    means that you used the anon hash constructor when you meant to use
    parens. In any case, a hash requires key/value pairs.

        %hash = { one => 1, two => 2, };    # WRONG
        %hash = [ qw/ an anon array / ];    # WRONG
        %hash = ( one => 1, two => 2, );    # right
        %hash = qw( one 1 two 2 );          # also fine

---

当我运行您的代码时，Perl准确地告诉了我问题所在

$ ./hash
Reference found where even-sized list expected at ./hash line 7.
Reference found where even-sized list expected at ./hash line 30.
Use of uninitialized value in print at ./hash line 34.
Reference found where even-sized list expected at ./hash line 30.
Use of uninitialized value in print at ./hash line 34.
Reference found where even-sized list expected at ./hash line 30.
Use of uninitialized value in print at ./hash line 34.

如果不清楚，您可以打开诊断以获得更详细的描述

$ perl -Mdiagnostics hash
Reference found where even-sized list expected at hash line 7 (#1)
    (W misc) You gave a single reference where Perl was expecting a list
    with an even number of elements (for assignment to a hash). This usually
    means that you used the anon hash constructor when you meant to use
    parens. In any case, a hash requires key/value pairs.

        %hash = { one => 1, two => 2, };    # WRONG
        %hash = [ qw/ an anon array / ];    # WRONG
        %hash = ( one => 1, two => 2, );    # right
        %hash = qw( one 1 two 2 );          # also fine

---

如果$author和$dig确实仅用作键，则可以通过循环使用标题中的值来简化它。如果$author和$dig确实仅用作键，则可以通过循环使用值来简化它