Hash keys are always strings, so if you try to use undef it will be coerced to the empty string, with a warning ("Use of uninitialized value in hash element") if warnings are enabled. So it shouldn't actually be possible for that code to be called.

In reply to Re: undef as a key in a hash. by Eimi Metamorphoumai
in thread undef as a key in a hash. by fenLisesi

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