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NOTE: Only applies to primitive types, i.e., int i; Currently, Eclipse warns that "i = i;" has no effect. It would be nice to expand this analysis to also detect that "i = i++;" has no effect.
Trivial addition, and good idea.
Added AssignmentTest#test035. Fixed
The idea is from Josh Block and Neal Gafter, sadly my only contribution is that it might be a good warning to add into Eclipse...Thanks!
I ment Josh Bloch (typo)
Verified in I20050214
Actually, this is wrong. In "i = i++;", the assignment is not a noop. The postfix increment is. As a consequence, "i = i++" is equivalent to doing nothing. Current implementation simply removes the assignment, and leaves the postfix increment.
Also see bug 111898. Will remove detection for this scenario. I can automate the entire deletion of the statement, but then need to introduce a specific new problem for this case, since the suggestion for discarding only the assignment is misleading. b = b++; is not equivalent to: b++; I do not believe this pattern is frequent enough to justify a custom problem for it.
I disagree, this pattern is common enough to appear in Java Puzzlers by Bloch and Gafter. In addition, there is no argument that "i = i++;" is the same as "i++;" however -- usually the latter is what the programmer wanted to do. I've also seen it student code (undergraduate and graduate level) when students who are fuzzy about the semantics of the ++ operator "try" it out. It clearly is a noop -- however I do concur the light bulb should probably have two options: (1) replace with "i++" or (2) remove the statment;
Java puzzlers are not common patterns, simply weird corner cases. I agree it would be nice to flag, but it must be flagged distinctly from an assignment with no effect, as it does not get fixed in the same way.
