Perl 如何使哈希在另一个模块中可用

首先，您不能使用“my”来声明它，因为它声明的是词汇变量，而不是包变量。使用

our

可以引用包变量并为其指定所需的值。然后在另一个包中，用第一个包的名称作为变量名称的前缀

use

不像C#

using

语句，因为它不从另一个包导入符号，它只是让符号可用

类似的内容应该能够证明：

for Ex : 
package test1 ; 

my %hash = ( a=> 10 , b => 30 ) ;

1;

in Script : 

use test1 ;

print %hash ;  # How to  make this avilable in script without sub

---

良好的编程实践规定，您不允许外来代码直接干扰模块的数据，相反，它们必须通过中介，例如访问器例程

TIMTOWTDI，带和不带出口。Moose示例看起来很长，但这一示例还允许设置数据，而不是仅从

Test1

读取数据，其他三个示例需要相当多的额外代码来处理这种情况

---

无装饰 模块

use strict;
use warnings;

package test1; 

our %hash = ( a=> 10 , b => 30 ) ;

package test2;

print $test1::hash{a} ; #prints 10

use Test1 qw();
Test1::member_data; # returns (a => 10, b => 30)

use Test1 qw();
Test1->new->member_data; # returns {a => 10, b => 30}
# can also set/write data!  ->member_data(\%something_new)

use Test1 qw(member_data);
member_data; # returns (a => 10, b => 30)

节目

package Test1;
{
    my %hash = (a => 10, b => 30);
    sub member_data { return %hash; }
}
1;

package Test1;
use Moose;
has 'member_data' => (is => 'rw', isa => 'HashRef', default => sub { return {a => 10, b => 30}; });
1;

package Test1;
use Sub::Exporter -setup => { exports => [ qw(member_data) ] };

{
    my %hash = (a => 10, b => 30);
    sub member_data { return %hash; }
}
1;

package Test1;
use parent 'Exporter';

our @EXPORT_OK = qw(member_data);

{
    my %hash = (a => 10, b => 30);
    sub member_data { return %hash; }
}
1;

---

驼鹿 模块

use strict;
use warnings;

package test1; 

our %hash = ( a=> 10 , b => 30 ) ;

package test2;

print $test1::hash{a} ; #prints 10

use Test1 qw();
Test1::member_data; # returns (a => 10, b => 30)

use Test1 qw();
Test1->new->member_data; # returns {a => 10, b => 30}
# can also set/write data!  ->member_data(\%something_new)

use Test1 qw(member_data);
member_data; # returns (a => 10, b => 30)

节目

package Test1;
{
    my %hash = (a => 10, b => 30);
    sub member_data { return %hash; }
}
1;

package Test1;
use Moose;
has 'member_data' => (is => 'rw', isa => 'HashRef', default => sub { return {a => 10, b => 30}; });
1;

package Test1;
use Sub::Exporter -setup => { exports => [ qw(member_data) ] };

{
    my %hash = (a => 10, b => 30);
    sub member_data { return %hash; }
}
1;

package Test1;
use parent 'Exporter';

our @EXPORT_OK = qw(member_data);

{
    my %hash = (a => 10, b => 30);
    sub member_data { return %hash; }
}
1;

---

次级：出口商 模块

use strict;
use warnings;

package test1; 

our %hash = ( a=> 10 , b => 30 ) ;

package test2;

print $test1::hash{a} ; #prints 10

use Test1 qw();
Test1::member_data; # returns (a => 10, b => 30)

use Test1 qw();
Test1->new->member_data; # returns {a => 10, b => 30}
# can also set/write data!  ->member_data(\%something_new)

use Test1 qw(member_data);
member_data; # returns (a => 10, b => 30)

节目

package Test1;
{
    my %hash = (a => 10, b => 30);
    sub member_data { return %hash; }
}
1;

package Test1;
use Moose;
has 'member_data' => (is => 'rw', isa => 'HashRef', default => sub { return {a => 10, b => 30}; });
1;

package Test1;
use Sub::Exporter -setup => { exports => [ qw(member_data) ] };

{
    my %hash = (a => 10, b => 30);
    sub member_data { return %hash; }
}
1;

package Test1;
use parent 'Exporter';

our @EXPORT_OK = qw(member_data);

{
    my %hash = (a => 10, b => 30);
    sub member_data { return %hash; }
}
1;

---

出口商 模块

use strict;
use warnings;

package test1; 

our %hash = ( a=> 10 , b => 30 ) ;

package test2;

print $test1::hash{a} ; #prints 10

use Test1 qw();
Test1::member_data; # returns (a => 10, b => 30)

use Test1 qw();
Test1->new->member_data; # returns {a => 10, b => 30}
# can also set/write data!  ->member_data(\%something_new)

use Test1 qw(member_data);
member_data; # returns (a => 10, b => 30)

节目

package Test1;
{
    my %hash = (a => 10, b => 30);
    sub member_data { return %hash; }
}
1;

package Test1;
use Moose;
has 'member_data' => (is => 'rw', isa => 'HashRef', default => sub { return {a => 10, b => 30}; });
1;

package Test1;
use Sub::Exporter -setup => { exports => [ qw(member_data) ] };

{
    my %hash = (a => 10, b => 30);
    sub member_data { return %hash; }
}
1;

package Test1;
use parent 'Exporter';

our @EXPORT_OK = qw(member_data);

{
    my %hash = (a => 10, b => 30);
    sub member_data { return %hash; }
}
1;

---

变量需要属于包才能导出。如果使用

our

而不是

my

声明哈希，则使用模块的脚本将能够使用其完全限定名访问哈希：

%test1:：hash

要更方便地导出符号，可以使用

也就是说，通常建议避免导出变量和所有与全局变量相关的问题

# The module.
package Bubb;

use strict;
use warnings;

use base qw(Exporter); # As of Perl 5.10: `use parent ...`

our @EXPORT_OK = qw(bar %fubb);

sub bar { 'bar' }

our %fubb = (fizz => 1, buzz => 2);

1;

# The script.
use Bubb qw(bar %fubb);

---

+回答得好。我正在我的代码中使用你的方法。因为那就是我想做的！upvote是因为我想使用这样的方法，但是对我来说，由于奇怪的原因，它不起作用，它对变量起作用，但对哈希不起作用，当通过花括号以哈希方式访问哈希变量索引时，它总是返回undef，因为它返回的变量为1/8。对于我来说，是什么让我像使用标准变量一样使用它，并通过arrow

our$hash={}，$test1:：hash->{a}

访问对象的方式工作的？您已经阅读了

perldoc perltoot

和

perldoc perltooc

对吗？