in reply to Checking Variable for Not Null

You haven't said what you understand by "null" in this context. "null" is not a concept in Perl. We have defined and we have true. eg:

ValueTrue?Defined?
undefNoNo
0NoYes
''NoYes
1YesYes
'TIMTOWTDI'YesYes

BTW, do you really find unless ! to be clearer than if?

Replies are listed 'Best First'.
Re^2: Checking Variable for Not Null
by dirtdog (Monk) on May 27, 2015 at 15:16 UTC

    Good point Hippo. If is much clearer.