有一个问题可以解释我想要的内容：
how to merge 2 deep hashes in perl
但是,那里的答案似乎对我不起作用(使用Merge模块的建议).
我有两个哈希像这样：
$VAR1 = {
'57494' => {
'name' => 'John Smith','age' => '9','height' => '120'
},'57495' => {
'name' => 'Amy Pond','age' => '17','height' => '168'
}
}
};
$VAR1 = {
'57494' => {
'name_address' => 'Peter Smith','address' => '5 Cambridge Road','post_code' => 'CR5 0FS'
}
}
};
如果我使用Hash :: Merge或％c = {％a,％b}格式,我每次都会得到这个：
$VAR1 = '57494';
$VAR2 = {
'name_address' => 'Peter Smith','post_code' => 'CR5 0FS'
};
(所以当我想要时,它基本上用第二个数据覆盖了第一个数据并弄乱了键)：
$VAR1 = {
'57494' => {
'name' => 'John Smith','height' => '120'
'name_address' => 'Peter Smith','post_code' => 'CR5 0FS'
},'height' => '168'
}
}
};
因此,当密钥相同时,数据会合并在一起,否则新密钥只会附加到末尾.我希望这是有道理的.也许我使用Merge做错了一些事情,或者需要“手动”将它们添加到循环中,但无论如何我都会花太多时间思考它！
编辑：我如何使用Merge来查看我是否在做一些愚蠢的事情：
我有：
use Hash::Merge qw( merge );
...hash data above as %hash1 and %hash2...
my %combined_hash = %{ merge( %hash1,%hash2 ) };
print Dumper(%combined_hash);
解决方法
如果我用引用来做它,它就像一个魅力.
use strict; use warnings;
use Data::Dumper;
use Hash::Merge qw(merge);
my $h1 = {
'57494' => {
'name' => 'John Smith','age' => '9','height' => '120'
},'57495' => {
'name' => 'Amy Pond','age' => '17','height' => '168'
}
};
my $h2 = {
'57494' => {
'name_address' => 'Peter Smith','address' => '5 Cambridge Road','post_code' => 'CR5 0FS'
}
};
my $h3 = merge( $h1,$h2 );
print Dumper $h3;
输出：
$VAR1 = {
'57495' => {
'name' => 'Amy Pond','height' => '168'
},'57494' => {
'name_address' => 'Peter Smith','name' => 'John Smith','post_code' => 'CR5 0FS','height' => '120','age' => '9'
}
};
但是,如果我使用散列而不是散列引用来执行此操作,则不会：
my %hash1 = (
'57494' => {
'name' => 'John Smith','height' => '168'
}
);
my %hash2 = (
'57494' => {
'name_address' => 'Peter Smith','post_code' => 'CR5 0FS'
}
);
my %h3 = merge( %hash1,%hash2 );
print Dumper \%h3;
__END__
$VAR1 = {
'57495' => undef
};
这是因为Hash::Merge的合并只能接受引用,但是你传递它的哈希值.此外,您需要在标量上下文中调用它.
试试吧：
# +--------+--- references
#,-- SCALAR context | |
my $combined_hash = %{ merge( \%hash1,\%hash2 ) };
print Dumper($combined_hash);