The problem is that and has very loose precedence, looser than the assignment operator. So you need to write $a && $b or ($a and $b). See perlop for more details.

In Perl 5, the false value is represented as an empty string that can numify to 0 without a warning. That's what you are seeing in your second attempt.

Perl 6 - second systems done right

In reply to Re: strange boolean algebra behaviour by moritz
in thread strange boolean algebra behaviour by vlad_tepesch

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