First off, you are passing a hash, but calling it list so the example below uses a list (array).

use strict;
use warnings;

my @list = (1, 2, 3, 4);
my $value = 10;

whatever (\@list, $value);

sub whatever
{
my @localList = @{$_[0]}; #Deref first (reference) param
my $localValue = $_[1];

print join ", ", @localList;
print " - $localValue";
}
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You need to pass the array as a reference because otherwise it will be flattened, which is not what you want.