I'm not entirely sure what the question is, but you may be experiencing autovivification. Here's an example:

use Data::Dumper;

my %empty_hash = ();

if (exists $empty_hash{foo}) {
    print "'foo' exists\n";
}

if (exists $empty_hash{foo}{bar}) {
    print "'foo'->'bar' exists\n";
}

print Dumper \%empty_hash;

if (exists $empty_hash{foo}) {
    print "Oh look, now 'foo' exists\n";
}

[download]

The autovivification module on CPAN can be used to disable autovivification for particular blocks of code where it's causing issues.

perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'

In reply to Re: Not meaning to add values to a hash by tobyink
in thread Not meaning to add values to a hash by stu96art

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