Hashes can have duplicate VALUES, but not duplicate KEYS. You assigned a value to the key of '', probably because your assignment statement's left side's key expression evaluated to undef. (Undef stringizes as ''.)

I shouldn't scan so quickly, the odd values-first printout threw me off. However, this should explain your odd "duplicate keys" mystery. 

%hash = (
          '1' => 'angel',
          '2' => 'buffy',
          '3' => 'cordelia',
          '4' => 'dawn',
          '5' => 'ethan'
          '54' => undef,
          '6' => 'faith',
          '7' => 'giles',
        );

[download]

The printf "%d" turned the key '5 4' into an integer '5'.

--
[ e d @ h a l l e y . c c ]

In reply to Re: Swapping Two Hash Values by halley
in thread Swapping Two Hash Values by Cody Pendant

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