use strict;
use warnings;
my @load_array = (1,2,3);
my %load_number_hash = ();
foreach(@load_array){
     $load_number_hash{$_} = $_;
}

%load_number_hash = ();
print $load_number_hash{1};
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If you mean above, you are right.. It gives me warning. IMHO, it is correct. You can possibly store your hash-keys in another hash. In order to be defined for the hash $hash{$key} is necessary which is not preserved after 'deletion' or undef operation on hash items

artist