git - diff current working copy of a file with another branch's committed copy

Question

I have a repo with file foo in the master branch. I switched to bar branch and made some changes to foo. How can I now run a git diff between this copy (which isn't committed yet) and the copy of the master branch?

Answer 1

The following works for me:

git diff master:foo foo

In the past, it may have been:

git diff foo master:foo