Thanks for the info. The exists documentation does warn that your first example of autovivification ($h{$i}{$j}) will autovivify even if you're checking with exists. That is, 
{
   my %h;
   1 if exists $h{foo}{bar};
   print("exists 2:  ", (%h ? "auto-vivi" : "empty"), "\n");
}

[download]
prints "auto-vivi".

But for some reason I thought it was easier to autovivify keys.

In reply to Re^4: Hashing it out: defined? exists? by Nkuvu
in thread Hashing it out: defined? exists? by eff_i_g

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