如何在 foreach 循环中刷新数组?
我正在编写一个 Perl 脚本来对哈希值进行一些数学运算。该哈希值包含以下示例中给出的值。我写了下面的代码。如果我在不使用 foreach 循环的情况下单独对数组值执行此代码,则输出很好。但是,如果我对数组值使用 foreach 循环运行此操作,则 A 中的值的总和很好,但从 B 中输出会添加先前的值。
Hash Sample:
$VAR1 = 'A';
$VAR2 = {
'"x"' => [values],
'"y"' => [values],
and so on...
$VAR3 = 'B';
$VAR4 = {
'"x"' => [values],
'"y"' => [values],
and so on...
$VARn....
代码:
#!/usr/bin/perl -w
use strict;
use List::Util qw(sum);
my @data;
my @count;
my $total;
my @array = ("A", "B", "C", "D");
foreach my $v (@array) {
my %table = getV($v); #getV is a subroutine returing a hash.
for my $h (sort keys %table) {
for my $et (sort keys %{ $table{$h} } ) {
for $ec ($table{$h}{$et}) {
push @data, $ec;
@count = map { sum(@{$_}) } @data;
$total = sum(@count);
}
}
print "sum of $v is $total\n";
}
我认为问题出在这一行。它存储所有以前的值,因此在下一个 foreach 循环中添加所有值。
push @data, $ec;
所以,这里我有两个问题:
1)如何在每次 foreach 循环迭代中刷新数组(@data)?
2) 如何添加数组 ref ($ec) 中的值并将它们存储在数组中?因为当我使用以下代码时:
for $ec ($table{$h}{$et}) {
@count = map { sum(@{$_}) } @$ec;
$total = sum(@count);
}
输出为我提供了相同的 @count 和 $total 值。
请给我提供建议。
I am writing a Perl script to do some mathematical operations on a hash. This hash contains the values as given in the sample below. I have written the code below. If I execute this code for an array value separately without using a foreach loop, the output is fine. But if I run this using a foreach loop on the array values, the sum for values in A are good, but from B the output add the previous values.
Hash Sample:
$VAR1 = 'A';
$VAR2 = {
'"x"' => [values],
'"y"' => [values],
and so on...
$VAR3 = 'B';
$VAR4 = {
'"x"' => [values],
'"y"' => [values],
and so on...
$VARn....
Code:
#!/usr/bin/perl -w
use strict;
use List::Util qw(sum);
my @data;
my @count;
my $total;
my @array = ("A", "B", "C", "D");
foreach my $v (@array) {
my %table = getV($v); #getV is a subroutine returing a hash.
for my $h (sort keys %table) {
for my $et (sort keys %{ $table{$h} } ) {
for $ec ($table{$h}{$et}) {
push @data, $ec;
@count = map { sum(@{$_}) } @data;
$total = sum(@count);
}
}
print "sum of $v is $total\n";
}
I think the issue is with this line. It is storing all the previous values and hence adding all the values in next foreach loop.
push @data, $ec;
So, here I have two issues:
1) How can I refresh the array (@data) in each foreach loop iteration?
2) How can I add the values in the array ref ($ec) and store them in an array? Because when I use the following code:
for $ec ($table{$h}{$et}) {
@count = map { sum(@{$_}) } @$ec;
$total = sum(@count);
}
The output gives me the same values for @count and $total.
Please provide me with suggestions.
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如果我理解正确的话,只需对您的代码进行一点小小的更改即可。在 for 循环的开头创建一个空数组 (
@data
)。希望这有帮助。If I understand you correctly, just a small change in your code. Make an empty array (
@data
) at the beginning of for loop. Hope this helps.1) 在循环体的顶部声明 @data 数组,您希望从一个新的空数组开始。或者也许您的意思是说
@data = @$ec
,而不是push @data, $ec
?2) 要添加 $ec 引用的数组中的值,只需输入
sum(@$ec)
;不需要地图。目前尚不完全清楚您的数据结构是什么或您想用它做什么。
这将有助于了解示例 %table 的外观以及您期望从中得到的结果。
1) Declare the @data array at the top of the loop body where you want to start with a fresh, empty array. Or maybe you mean to be saying
@data = @$ec
, notpush @data, $ec
?2) To add the values in the array referred to by $ec, you would just say
sum(@$ec)
; no map required.It's not completely clear what your data structure is or what you are trying to do with it.
It would help to see what a sample %table looks like and what results you expect from it.