>>>>> "APK" == Akhthar Parvez K <[email protected]> writes:
APK> There was a typo in my original email. I missed the word "not" which was
very crucial as always.
APK> Scenario: #1
APK> unless ( (defined $result) && ($test !~ /TEST/) )
i recomment never using !~ as it doesn't read well and it makes for poor
boolean tests. also i rarely use unless for complex (2 or more) boolean
ops for the same reason.
APK> { my $result = "OK";
APK> print "$result\n";
APK> }
APK> I thought it was:
APK> UNLESS $result is defined and UNLESS $test does not contain TEST = IF
$result is not defined and if $test contains TEST.
no, that is not boolean logic. the && happens first and then the unless
inverts that for the conditional test. a conditional is always only one
boolean value that must be derived from the expression. unless/if
doesn't see the multiple parts.
APK> Scenario: #2
APK> unless (defined $result)
APK> {
APK> unless ($test !~ /TEST/)
APK> { my $result = "OK";
APK> print "$result\n";
APK> }
APK> }
APK> This would work as I thought (UNLESS $result is defined and
APK> UNLESS $test does not contain TEST), but not the scenario #1.
that is two separate boolean tests so it works as you think it does. if
you inverted the earlier unless by applying demorgan's law it would look
like this:
if ( ! defined $result || $test =~ /TEST/ ) {
you can read it better and see what is really happening. if you don't
have a result OR the test is a TEST, then do this. use my boolean rules
above and you won't run into this confusion as much.
uri
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