perl - Perl％{$ var}与％$ var

%{$var}和%$var有什么区别？我尝试了这段代码，但是有错误：


每个引用在test.pl第21行都是实验性的。
对每个引用的引用都必须在test.pl处为unhlessed hashref或arrayref
第21行

use feature 'say';

%HoH = (
    1 => {
        husband   => "fred",
        pal       => "barney",
    },
    2 => {
        husband   => "george",
        wife      => "jane",
        "his boy" => "elroy",
    },
    3 => {
        husband   => "homer",
        wife      => "marge",
        kid       => "bart",
    },
);

for ($i = 1; $i <= 3; $i++) {
    while ( ($family, $roles) = each %$HoH{$i} ) {
        say "$family: $roles";
    }
}

但是这段代码可以正常工作：

use feature 'say';

%HoH = (
    1 => {
        husband   => "fred",
        pal       => "barney",
    },
    2 => {
        husband   => "george",
        wife      => "jane",
        "his boy" => "elroy",
    },
    3 => {
        husband   => "homer",
        wife      => "marge",
        kid       => "bart",
    },
);

for ($i = 1; $i <= 3; $i++) {
    while ( ($family, $roles) = each %{$HoH{$i}} ) {
        say "$family: $roles";
    }
}

最佳答案

使用%$HoH{$i}可以将$ HoH用作哈希引用，而使用%{$HoH{$i}}可以将$HoH{$i}用作哈希引用，这就是你想要的...而且，代码上的use strict :-)