Independent of your solution to fionbarr's question and his real intention, I have tried to correct his code in the following way: 

use strict;
use warnings;

my %hash;
my $label = "label";
my $value = "value";

# this does not work !!!
@hash{ 'a'..'h' } = ( { $label => $value } ) x 9;

$hash{ 'a' }{ $label } = "newvalue";
print $hash{ 'b' }{ $label },"\n"; # is "newvalue" !!!

[download]

This results in a structure where $hash{'a'} to $hash{'h'} all point to the same hash, so changing one changes all of them.

Is there a way to have the x operator really create 9 independent hash refs? (If this is helpful here or not is a different question.)

The following code works but is too cumbersome. 


use strict;
use warnings;

my %hash;
my $label = "label";
my $value = "value";

# this works !!!
@hash{ 'a'..'h' } = ( { $label => $value },
              { $label => $value },
              { $label => $value },
              { $label => $value },
              { $label => $value },
              { $label => $value },
              { $label => $value },
              { $label => $value },
              { $label => $value }, );

$hash{ 'a' }{ $label } = "newvalue";
print $hash{ 'b' }{ $label },"\n"; # is "value" !!!

[download]

In reply to Re^2: iterate through a hash with two keys by hdb
in thread iterate through a hash with two keys by fionbarr

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