http://www.perlmonks.org?node_id=428311


in reply to equivalent code for unless
in thread unless statements

unless ($boolean) { ... }
is nearly completely equivalent to:
if (not $boolean) { ... }
(The slight difference is in the "last expression evaluated" return value for a subroutine, but that's only a minor distracting point.)

-- Randal L. Schwartz, Perl hacker
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