Also see Uri Guttman's article on autovivification. It includes some sample code to check for hash keys at any level of a multi-level data structure without triggering autovivification. (paraphrased from description in article)

http://tlc.perlarchive.com/articles/perl/ug0002.shtml

--sacked

In reply to Re: Looping through a hash reference is creating a key...? by sacked
in thread Looping through a hash reference is creating a key...? by the_slycer

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