Not a dumb question, by any means. I'd say the middle one prints nothing, because $a-- returns the value of $a before the decrement, ie undef. I can think of no good reason, however, for the first to print 0 - that looks like a bug to me.

Looking at the source, there appears to be some special code in the handling of post-increment to cater for this, and it has been there for a long time - at least as far back as perl5.003. But there isn't any indication of a reason for this special handling, and removing it causes only one test failure that doesn't look to be intentionally testing this feature.

I've reported this to the perl development mailing list along with a suggested patch to see if anyone has an idea why this special-case should exist.

Hugo

In reply to Re: dumb question by hv
in thread post-increment and post-decrement behavior (was: dumb question) by Anonymous Monk

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