perl - Perl：如何在子例程中更改全局哈希值

Question

我有一个全局哈希

our %employee = (
    'ename'=>"rahul",
    'eno'=>"25",
);

稍后我想在具有不同值的子程序中使用它

sub emp
{
    print ("$employee->'ename' = 'satish'");
}

但这没有发生，你能告诉我这里有什么问题吗..？

Answer 1

%employee是哈希而不是哈希引用。所以尝试修改值$employee{'ename'}= "Satish";

use strict;

our %employee = ( 
    'ename' => "rahul",
    'eno'   => "25",
);

sub emp {
    print "Original Value: $employee{'ename'} \n";
    $employee{'ename'} = "Satish";
    print "Modified Value: $employee{'ename'}\n";
}

emp();

输出：

Original Value: rahul
Modified Value: Satish

Answer 2

就像你会修改另一个哈希值一样。

假设你有一个这样的包：

package TestPack;

use warnings;
use strict;

our %employee = (
    ename => 'rahul',
    eno   => 25,
);

你可以这样修改hash：

#!/usr/bin/perl

use warnings;
use strict;

use TestPack;

print "name: $TestPack::employee{'ename'}\n";

$TestPack::employee{'ename'} = "Chris";
print "name: $TestPack::employee{'ename'}\n";

输出：

$ ./test.pl 
name: rahul
name: Chris

虽然在与许多人一起处理大型项目时直接处理数据可能不是最好的，但您可以在以下位置使用“访问器/突变器”之类的东西TestPack：

sub get_value {
    my $val = shift;

    if( exists($employee{$val}) ) {
        return $employee{$val};
    } else {
        return "No such value: $val";
    }
}

sub update_ename {
    my $ename = shift;

    $employee{'ename'} = $ename;
}

另一个模块/脚本可以添加如下内容：

my $new_new_ename = "Mike";

TestPack::update_ename($new_new_ename);
print "name: ", TestPack::get_value('ename'), "\n";
print "name: ", TestPack::get_value('foobar'), "\n";

输出：

name: Mike
name: No such value: foobar