Code Commenting: Do you put your code comments on Interfaces or on Concrete classes, or both? [duplicate]

Answer 1

I don't really use them at all. Instead I make sure to structure the code and name all methods and variables in a way that its obvious what they do without comments. The problem with comments is that they don't compile and don't execute and are not tested by your unit tests, so its pretty much impossible to keep them in synch with the code.

Answer 2

Only for interfaces. Because in this case I don't need to synchronize them. My IDE helps me to see interface comments in concrete classes. And api document generator does the same.

Answer 3

I would put comments on both.

On interfaces I would comment on the intent behind the interface members and usage.

On implementations I would comment on the reasons for the specific implementation.