If you are interested in the implementation, we had a discussion here not long ago with pointers into the relevant doc.

Re: can I change hash keys or values directly

HTH! :)

update

In short, rehashing is expensive but only happens in doubling steps, which makes the costs constant in average.

Cheers Rolf
(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery

In reply to Re: Performance of hash and array inserts by LanX
in thread Performance of hash and array inserts by bliako

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