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So we learned a lot about commits

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and branches now and so far,

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we only added data to our well, Git-managed project here.

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Now is the time to also delete information.

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And for this, I will leave our main branch here

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and first create a new branch.

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So we can run git checkout -b,

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and now a new branch name.

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I'll just call it delete

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because we will delete well, data in this branch.

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So we are in this branch now

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and in this branch, I'll add a new folder maybe.

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Not in here, maybe right there.

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I'm deleting-data.

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This one.

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And in there, I'll add a new file.

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So file1.txt.

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We'll then add this file and commit it.

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Added file1.txt.

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Then we'll add some dummy text in here

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just to show you how deletion works.

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For this, we need some additional commits.

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Just some text to dive deeper here.

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We'll also save this.

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Added, now it's working.

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So git add dot

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and git commit -m.

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Added text to file1.txt maybe.

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Like this.

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And let's clear this.

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And now we'll add a third commit

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where we could say some more

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text in here.

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And finally, our last commit.

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Added more text.

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Not too important here what the commit says.

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And now besides this first file here,

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I would like to add two more files.

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Let's quickly do this.

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So file2.txt.

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And also commit this.

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Commit -m.

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Added file2.txt.

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And now we'll add a third file here.

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File3.txt,

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which we'll also add as a separate commit.

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And git commit -m file3.txt.

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I know lots of commits we just created here

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but to understand how deleting works,

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well, it's great to have these examples.

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We can also clear this again

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and now log our information,

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and so we see well, we have some data to play with now.

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I would like to get started with a very well,

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simple operation actually,

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and this is deleting files from the working directory.

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As you saw, the three files we added now

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are part of previous commits.

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Therefore, these are all tracked files,

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and to delete these, well, we have two options basically.

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A very common one, of course, is to simply well,

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right click onto the file

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and press Delete, and then you can move it to the trash.

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With this, and by checking its status,

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you see that we have to add this deleted file so to say

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to the staging area

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because we have unstaged changes to be committed,

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so we have to tell Git that this file should be executed.

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Alternatively, we can also run git rm

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and now refer to the file name.

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File2.txt, like this, so git rm for remove.

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And there you see this doesn't work.

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Why's it not working?

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Well, because currently we are in the git-basics folder

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but to delete a specific file without specifying a path,

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we have to navigate into this path,

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so with cd deleting-data,

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we are in the correct path now.

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And in there, we can now run git remove file2.txt.

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With that, you see that the file was deleted.

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And by running git status once again,

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you see that we have a difference here.

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If we delete the file from the working directory

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as we did it,

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we have to add this change to the staging area first.

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You can see this down here.

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This is the deleted file with that red text,

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and these changes are not staged.

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I mentioned this already.

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Up here, when we use the git remove command,

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we see that the changes can be immediately committed.

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So with this, this means Git automatically removes the file

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from the staging area for us.

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Therefore, if you just want to delete files,

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git remove or git rm saves you the additional adding

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to the staging area step.

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Nevertheless, we can, of course, add this

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because we have to add the file we deleted

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with the right click

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and then we can commit this and say deleted file2 and file3.

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Like this.

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And with that, if we check the status,

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you see everything is cool, nothing to commit.

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We can also close this window now

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and focus onto file1.txt

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because besides deleting working directory files,

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we might also want to delete individual commits

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or to be more precise here,

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we might want to go back to an earlier stage

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of our project, and therefore,

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delete the latest commit, for example.

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If we go to our git log here,

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you see that currently our HEAD

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is here in the latest commit.

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No big surprise.

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But what if we want to revert this change now?

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What if this should be deleted

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and we say well, actually, I would like

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to have this commit back

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where we had the second and the third file?

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Well, this can be done.

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And for this, we use a command named git reset now,

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well, to reset what?

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Basically the so-called head,

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so the head is the pointer towards this latest commit

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in our branch.

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And this should now point to well, one commit earlier.

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And to make sure we don't only reset the head,

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but that we also exclude the latest commit changes

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from the staging area

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and to basically get rid of this entire commit,

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we have to add this --hard command here.

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This means it will update the so-called index

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and the path.

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I'll not dive too deep into this at this stage

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of this module

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because the important thing that you have to keep in mind

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is with adding --hard to this reset command,

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you will kind of be able to jump back

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to an earlier commit.

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And this jumping back now works

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with the so-called HEAD command.

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As I said, the HEAD is just the pointer,

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and this pointer should now, for example,

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go back to well, one commit earlier.

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This would be ~1.

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So the head goes back one commit, HEAD~1

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and --hard also make sure

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that this is a hard reset,

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so this means we update the so-called index

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and the path, and this means we simply kind

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of delete the latest commit entirely,

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so all changes applied right there

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are removed from the repository

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and also from the staging area.

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If we do this now,

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we see that well, magically,

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our file2 and file3 are back.

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And if we now check our log,

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you see that the latest commit is no longer displayed.

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Now our file3.txt here is the latest commit

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in our branch, the HEAD points to this commit,

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and also if we quit this,

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clear it and check our staging area,

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you see everything is clean, nothing to commit.

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We could also jump back multiple commits.

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This would then be git reset --hard and then HEAD.

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Well, ~1, 2, 3 and so on.

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This would also be possible.

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But generally, this is how you jump back to earlier commits

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by, at the same time, deleting the later commits you had

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in your branch.

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Now, talking about branches,

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let me delete this quickly,

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at the moment, we have well, three branches in our project.

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This delete branch is a branch we can keep for the moment

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but the feature branch is something no longer needed.

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We merged the feature branch

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into main already, therefore we can't delete this branch.

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To delete a branch,

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you have to check out another branch

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than the one you want to delete

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because otherwise you would delete

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your current position so to say.

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In our case, we are in the delete branch.

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Therefore, we can just run git branch dash capital D,

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that's important here, it must be a capital D,

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and now simply add the branch name.

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In our case, we add feature here.

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We confirm this,

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and we also get the information in Git

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that the branch named feature was deleted,

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and with git branch,

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we see that we only have two branches left now.

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So this is how we can change files

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from the working directory,

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how we can delete commits so to say,

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and how we can delete branches.

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There are only two core features you might typically use

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in your project

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and this is how we can get rid of unstaged

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and staged changes?

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Let's get started with the unstaged change here.

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I'm here in this file1.txt file

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and in there, I add well, more content so to say.

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Let's save this.

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And if I now check my git status,

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then no big surprise,

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I have changes not staged for commit,

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so unstaged changes.

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What if you want to revert these?

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Then you simply check out the latest committed stage

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of your project so to say,

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so the situation you had

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when checking out this branch.

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This works with git checkout -- and then a dot.

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This will simply reset your branch so to say

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to the stage of the latest commit.

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If you do that, you see this text is gone.

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By the way, in case you're wondering,

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what happens if I add some text here once again?

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And then say okay, I can just check out the main branch

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and then jump back to the delete branch maybe

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to get rid of this text

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and to have access to the latest commit in that branch.

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Do this with git checkout main, for example.

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But if you try this,

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you see that this is not working.

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We have to commit our changes or stash them.

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Stashing is a bit more advanced

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and therefore not the core focus of this course here.

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Therefore, for us, this means,

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we can again run git checkout --. to get rid of this text

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as we just learned it a few seconds ago.

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So these unstaged changes and how to revert these.

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What about staged changes now as a final step

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in this lecture?

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Well, for this, I'll add some changes

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to be staged so to say.

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Saving it.

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Now I'll add it to the staging area.

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I just add all changes with git add dot again.

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And now I say well, actually I see

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that these changes are ready in the staging area

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but actually, I don't want these changes to be part

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of my next commit.

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You could use this git restore command for this case here.

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That's one approach.

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I'll show you an alternative one though.

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And this is simply git reset,

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and now we refer to the file name,

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so file1.txt in our case.

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This is step one.

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With this, if we now check our status,

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you see that now we have changes not staged for commit,

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so this is basically the same logic

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that we had before when undoing unstaged changes.

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So in this case, we can simply run again git checkout --.

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to undo all unstaged changes.

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Or we simply reset the individual file,

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so this would be file1.txt in our case,

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and with this in place, you see that the text is deleted,

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and if we clear this now,

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and check the status, you see everything is clear,

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nothing to commit.

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With this, I also want to conclude this Git part

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of this module.

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So far, we only worked locally on our project

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but there is more to explore in the Git world,

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and to explore more, we have to leave our local environment

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and dive into the world of GitHub now.