Commenting code that is removed [closed]

Answer 1

There are some (rare) situations when commenting code out (instead of deleting) is a good idea. Here's one.

I had a line of code that seemed good and necessary. Later I realized that it is unnecessary and harmful. Instead of deleting the line, I commented it out, adding another comment: "The line below is wrong for such and such reason". Why?

Because I am sure next reader of the code will first think that not having this line is an error and will try to add it back. (Even if the reader is me two years from now.) I don't expect him to consult source control first. I need to add comment to warn him of this tricky situation; and having wrong line and the reason why it is wrong happened to be the best way to do so.