Arrays 如何在Perl中迭代对哈希数组的引用?
我有一个对hase数组的引用,我在perl脚本中传递给一个子例程 代码如下:Arrays 如何在Perl中迭代对哈希数组的引用?,arrays,perl,perl-data-structures,hash,Arrays,Perl,Perl Data Structures,Hash,我有一个对hase数组的引用,我在perl脚本中传递给一个子例程 代码如下: sub mySub { (my $resultref) = @_; my @list = @$resultref; print Dumper(@list); foreach my $result (@list) { print Dumper($result); } } 这是输出: $VAR1 = [ { 'portNa
sub mySub {
(my $resultref) = @_;
my @list = @$resultref;
print Dumper(@list);
foreach my $result (@list) {
print Dumper($result);
}
}
这是输出:
$VAR1 = [
{
'portName' => '1.1',
'ips' => [
'192.168.1.242'
],
'switchIp' => '192.168.1.20',
'macs' => [
'00:16:76:9e:63:47'
]
},
{
'portName' => '1.10',
'ips' => [
'192.168.1.119',
'192.168.1.3'
],
'switchIp' => '192.168.1.20',
'macs' => [
'd0:67:e5:f8:7e:7e',
'd0:67:e5:f8:7e:76'
]
},
];
$VAR1 = [
{
'portName' => '1.1',
'ips' => [
'192.168.1.242'
],
'switchIp' => '192.168.1.20',
'macs' => [
'00:16:76:9e:63:47'
]
},
{
'portName' => '1.10',
'ips' => [
'192.168.1.119',
'192.168.1.3'
],
'switchIp' => '192.168.1.20',
'macs' => [
'd0:67:e5:f8:7e:7e',
'd0:67:e5:f8:7e:76'
]
},
];
循环将整个数组放入$result变量中。我尝试将其作为@$result[0]取消引用,但未成功
如何分别循环这些散列
谢谢
我引用了一个hase数组
否,您已将对引用数组的引用传递给哈希数组
如果删除外部间接层,则代码可以按需要工作。传递给
mySub
的参数是对数组引用的引用。要迭代嵌套数组,可以执行以下操作:
sub mySub {
my ($resultref) = @_;
for my $result (@$resultref) {
my @list = @$result; # array of hashrefs
...
}
}
's转储程序
函数的参数应该是引用。例如:
use Data::Dumper;
my @array = ([1,2,3], [11,22,33]); # Two-dimensional array
print Dumper @array; # print array
print Dumper \@array; # print reference to array
输出:
$VAR1 = [
1,
2,
3
];
$VAR2 = [
11,
22,
33
];
$VAR1 = [
[
1,
2,
3
],
[
11,
22,
33
]
];
第二次打印在一个变量中给出了整个结构。当您直接打印数组时,它将扩展到其所有元素,因此
print Dumper @array;
相当于:
print Dumper $array[0], $array[1], ..., $array[$#array];
因此,在您的情况下,只需执行以下操作:
sub mySub {
my ($resultref) = @_;
print Dumper $resultref;
}
访问内部变量:
$VAR1 = [
1,
2,
3
];
$VAR2 = [
11,
22,
33
];
$VAR1 = [
[
1,
2,
3
],
[
11,
22,
33
]
];
只需看看数据::转储程序的输出:
$VAR1 = [ # bracket denotes start of an array ref
{ # curly brackets = hash ref
'portName' => '1.1',
'ips' => [
'192.168.1.242'
],
'switchIp' => '192.168.1.20',
'macs' => [
'00:16:76:9e:63:47'
]
}, # hash ref ends, comma = new array element begins
{ # new hash ref
'portName' => '1.10',
'ips' => [
'192.168.1.119',
'192.168.1.3'
],
'switchIp' => '192.168.1.20',
'macs' => [
'd0:67:e5:f8:7e:7e',
'd0:67:e5:f8:7e:76'
]
}, # end of hash
]; # end of array
这里需要注意的是,数组的所有元素和散列的所有值都是标量。因此,所有哈希和数组都可以很容易地分解成一个标量列表
for my $aref (@$resultref) { # starting array ref
for my $aref2 (@$aref) { # second level array ref
for my $href (@$aref2) # here begins the hash
local $\ = "\n"; # add newline to print for simplicity
print $href->{portName}; # printing a scalar
print for @{$href_>{ips}}; # printing an array ref w post-script loop
print $href->{switchIp};
print for @{$href->{macs}};
}
}
}
请注意使用箭头操作符取消引用。如果您有一个散列或数组,您可以执行$array[0]
或$hash{$key}
,但通过使用引用,您可以“指向”引用中包含的地址:$array->[0]
或$hash->{$key}
,谢谢,解释非常有用且完整