What runrig said.

The reason for having a warning about this is that while undef is a perfectly valid value for a variable, it has no textual representation. Printing it will render it as an empty string but Perl will warn you that what you're seeing may not be what you wanted. More often than not, having undefs printed indicates that you forgot to calculate/read/whatever some value.

In reply to Re: Annoying 'Use of uninitialized value in concatenation' warning by mbethke
in thread Annoying 'Use of uninitialized value in concatenation' warning by alain_desilets

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