Monks posting code and expecting all several hundred of us readers to run that code in order to learn from it is becoming a pet peeve of mine. The above code produces (when warnings are turned on):

Before: '
'

Use of uninitialized value in concatenation (.) at localundef.pl line 
+6.
After: ''
[download]

I will match you peeve for peeve.

If people see something that they do not understand, they should be willing to write small sample programs like the above, just to see what happens. If that leaves them with questions about why it works as it does, then ask. But first do some experiments.

Therefore I want to encourage people to read with a command prompt nearby, and I consider that encouragement to be worth having my comment go past some people who probably don't care enough about what I am talking about for it to stay in their memory.

I agree that encouraging people to debug their own problems is good. I disagree that encouraging a ton of people to cut'n'paste your 3 lines accomplishes that goal.

I also disagree in this specific case because I think that not obscuring an important point would be more valuable here than some trivial attempt to modify behavior.

If this had been, for example, a private e-mail reply to the question, then the weights shift and encouraging the original querist to actually try the code makes sense.

        - tye (but my friends call me "Tye")