Re: post-increment/pre-increment blues

The subject of autoincrement and side effects was discussed in this thread. Although we are not dealing with lvalue assignment to $i, as ariels has said, the result of the calculation is defined to be ambiguous in the C standard, and I guess the same is true of Perl. Hence you can get different results depending on platform, version and what mood the optimiser is feeling in :).

Comment on Re: post-increment/pre-increment blues

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To get 14... by SteveRoe (Novice) on Jun 19, 2002 at 16:13 UTC
`print ++$i + $i++ + 1;` Entering this line with i==5 prints (6+7+1) or (7+6+1). Sooo ++ has higher precedence than +. Certainly fun, but really not so hard to figure out why 14, eh?	[reply] [d/l]
Re: To get 14... by Abigail-II (Bishop) on Jun 19, 2002 at 16:34 UTC
`++` has higher precedence than `+`, but that's irrelevant. Precedence only determines how things are parsed. It does not determine the order of evaluation. As pointed out to people before, the value of the expression `++$i + $i++ + 1` is undefined. Any reasoning about what the value would be is a futile exercise. Any answer is as good (or wrong) as any other. Abigail	[reply] [d/l] [select]