Re^4: The mystery of double negation (bool 0)

Interestingly, !1 is "", ~~(!1) is 0, but ~~("") is "".

$ perl -MO=Deparse -E'say !1; say ~~(!1); say ~~("");'
use feature 'current_sub', 'evalbytes', 'fc', 'say', 'state', 'switch'
+, 'unicode_strings', 'unicode_eval';
say !1;
say 0;
say '';
-e syntax OK
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Re^5: The mystery of double negation (SvPOK) by tye (Sage) on Jul 13, 2015 at 21:51 UTC
Of course. `!1` is a dual-value of empty string plus 0. Bitwise operators operate on integers if the scalar has an authoritative ("public") numeric value, otherwise they operate on strings. QED. - tye	[reply] [d/l]


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