How to reverse the git diff output for uncommitted changes?

Question

I have some uncommitted, unstaged changes which I want to create a patch from, but also flip the + and - lines.

git diff shows a change like:

-apple
+orange

I want it to be like

+apple
-orange

but without committing the changes and then using a git diff commita..commitb

Answer 1

git diff -R

-R means "reverse".