For one, it's valid Perl syntax: 
D:\Temp>perl -c -e "if (not defined($pname) && $pname ne '' && defined
+($policy_ur) && $policy_ur ne '' && not defined($odate) && $odate ne 
+''){}"
-e syntax OK

[download]
But it's probably not doing what you expect: 
D:\Temp>perl -MO=Deparse,p -e "if (not defined($pname) && pname ne '' 
+&& defined($policy_ur) && $policy_ur ne '' && not defined($odate) && 
+$odate ne ''){}"
if (not defined $pname && $pname ne '' && defined $policy_ur && $polic
+y_ur ne ''
 && !(defined $odate && $odate ne '')) {
    ();
}
-e syntax OK

[download]
not has a much lower precedence than &&

use either not and and or ! and && in conjunction to get the intended effect.

Update: Seems like newly accuired syntax highlighting was distracting me ;-). Though a little bit complicated the assembly of the leading not (inverting the result of the whole test) with the && (chaining all the inner sub-tests together) makes sense.

In reply to Re: if not defined by pKai
in thread if not defined by Trihedralguy

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