The value it returns for false is not (simply) an empty string. It`s also zero in numerical context. 

>perl -wE"say 0+!1"
0

>perl -wE"say 0+''"
Argument "" isn't numeric in addition (+) at -e line 1.
0

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In reply to Re^2: Anybody use !! by ikegami
in thread Anybody use !! by Anonymous Monk

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