初学请教 哈希

zero_BX

大家好，看到一个帖子打印哈希二维的key，想请教下面代码高亮部分如何理解？为什么是@result，在这里表示数组吗？请大神赐教，谢谢了！

1. my %result;
   
2. $result{"a"}{"b"}=1;
   
3. $result{"a"}{"c"}=1;
   
4. 
   
5. my @a = keys <span style="background-color: Yellow;"> %{@result</span>{keys %result}};
   
6. print "@a";

复制代码

jason680

1. 有问要有回
  http://bbs.chinaunix.net/thread-4255120-1-1.html

2. 错误方法勿学
  试试
  $result{"a"}{"b"}=1;
  $result{"b"}{"c"}=1;

3. 看doc
$ perldoc perldata
NAME
    perldata - Perl data types

DESCRIPTION
  Variable names
    Perl has three built-in data types: scalars, arrays of scalars, and
    ...

    Scalar values are always named with '$', even when referring to a scalar
    that is part of an array or a hash. The '$' symbol works semantically like
    the English word "the" in that it indicates a single value is expected.

        $days               # the simple scalar value "days"
        $days[28]           # the 29th element of array @days
        $days{'Feb'}        # the 'Feb' value from hash %days
        $#days              # the last index of array @days

    Entire arrays (and slices of arrays and hashes) are denoted by '@', which
    works much as the word "these" or "those" does in English, in that it
    indicates multiple values are expected.

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

104359176

my @a = keys  %{@result{keys %result}};
print "@a";

dahe_1984

楼主什么意思？