I thought double quoting "0/1" would result in stringification and not an actual boolean.

"0" produces a string, but that is still false in boolean context.

You should really use exists: 

$hash{KEY1} = '1' unless exists $hash{KEY};

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Perl 6 - second systems done right

In reply to Re: Hashes and boolean values by moritz
in thread Hashes and boolean values by osbosb

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