Whats the difference between git reset --mixed, --soft, and --hard?

https://stackoverflow.com/questions/3528245/whats-the-difference-between-git-reset-mixed-soft-and-hard

When you modify a file in your repository, the change is initially unstaged. In order to commit it, you must stage it—that is, add it to the index—using

git add

. When you make a commit, the changes that are committed are those that have been added to the index.

git reset

changes, at minimum, where the current branch (

HEAD

) is pointing. The difference between

--mixed

and

--soft

is whether or not your index is also modified. So, if we're on branch

master

with this series of commits:

- A - B - C (master)

HEAD

points to

C

and the index matches

C

.

When we run

git reset --soft B

,

master

(and thus

HEAD

) now points to

B

, but the index still has the changes from

C

;

git status

will show them as staged. So if we run

git commit

at this point, we'll get a new commit with the same changes as

C

.

Okay, so starting from here again:

- A - B - C (master)

Now let's do

git reset --mixed B

. (Note:

--mixed

is the default option). Once again,

master

and

HEAD

point to B, but this time the index is also modified to match

B

. If we run

git commit

at this point, nothing will happen since the index matches

HEAD

. We still have the changes in the working directory, but since they're not in the index,

git status

shows them as unstaged. To commit them, you would

git add

and then commit as usual.

And finally,

--hard

is the same as

--mixed

(it changes your

HEAD

and index), except that

--hard

also modifies your working directory. If we're at

C

and run

git reset --hard B

, then the changes added in

C

, as well as any uncommitted changes you have, will be removed, and the files in your working copy will match commit

B

. Since you can permanently lose changes this way, you should always run

git status

before doing a hard reset to make sure your working directory is clean or that you're okay with losing your uncommitted changes.