I’m not a git expert and just arrived on this forum to understand it! Thus maybe my explanation is not perfect, sorry for that. I found all the other answer helpful and I will just try to give another perspective. I will modify a bit the question since I guess that it was maybe the intent of the author: “I’m new to git. Before using git, I was renaming my files like this: main.c, main_1.c, main_2.c when i was performing majors changes in order to be able to go back in case of trouble. Thus, if I decided to come back to main_1.c, it was easy and I also keep main_2.c and main_3.c since I could also need them later. How can I easily do the same thing using git?” For my answer, I mainly use the “regret number three” of the great answer of Matt above because I also think that the initial question is about “what do I do if I have regret when using git?”. At the beginning, the situation is like that:

a b c d(主)

第一个要点是创建一个新分支:git分支mynewbranch。然后一个得到:

(master和mynewbranch)

让我们假设现在有人想要回到A(前3次提交)。第二个要点是使用git reset命令——即使人们可以在网上读到这是危险的，也很难。是的，这很危险，但仅适用于未提交的更改。因此，这样做的方法是:

Git重置——commita的硬数字

or

Git复位-硬主~3

那么就得到: A (master) - B - C - D (mynewbranch)

Then, it’s possible to continue working and commit from A (master) but still can get an easy access to the other versions by checking out on the other branch: git checkout mynewbranch. Now, let’s imagine that one forgot to create a new branch before the command git reset --hard. Is the commit B, C, D are lost? No, but there are not stored in any branches. To find them again, one may use the command : git reflog that is consider as “a safety command”( “in case of trouble, keep calm and use git reflog”). This command will list all commits even those that not belong to any branches. Thus, it’s a convenient way to find the commit B, C or D.

简单回答这3个选项在什么情况下使用:

在代码中保留当前的更改，但要重写提交历史:

soft:你可以一次性提交所有内容，并使用新的描述创建一个新的提交(如果你使用tootise git或任何其他大多数gui，这是一个可以使用的，因为你仍然可以在提交中选择你想要的文件，并以这种方式对不同的文件进行多次提交。在Sourcetree中，所有文件都将被提交。) mixed:在提交之前，您必须将单独的文件再次添加到索引中(在Sourcetree中，所有更改的文件都将被取消staging)

要真正丢失您在代码中的更改:

难的是:你不仅重写了历史，而且还失去了你重置之前的所有更改

所有其他的答案都很棒，但我发现最好通过将文件分解为三类来理解它们:非阶段性、阶段性和提交:

——困难应该是容易理解的，它恢复了一切 ——mixed(默认): 非暂存文件:不要更改 暂存文件:移至非暂存文件 提交文件:移动到非暂存状态 ——软: 非暂存文件:不要更改 阶段性文件:不要更改 提交文件:移动到阶段性

总而言之:

-软选项将移动所有(除了非暂存文件)到暂存区 混合选项会把所有东西都移到非舞台区域

请注意，这是一个简化的解释，旨在作为寻求理解这个复杂功能的第一步。

对于那些想要在这些命令之后可视化他们的项目状态的视觉学习者来说，这可能是有帮助的:

给定:- A - B - C (master)

适用于开启彩色终端机的用户 (git配置——global color。ui汽车):

git重置-软A，你会看到B和C的东西在绿色(分期和准备提交)

git重置-混合A(或git重置A)，你会看到B和C的东西在红色(未分期和准备分期(绿色)，然后提交)

git重置-硬A，你将不再看到B和C的变化在任何地方(将好像他们从来没有存在过)

或者对于那些使用像“塔”或“SourceTree”这样的GUI程序的人

git重置——软A，你会看到B和C的东西在“阶段性文件”区域准备提交

git reset—混合A(或git reset A)，你会看到B和C的东西在“unstaging files”区域准备移动到staging，然后提交

git重置-硬A，你将不再看到B和C的变化在任何地方(将好像他们从来没有存在过)

你不必强迫自己记住它们之间的区别。想想你是如何做出承诺的。

做一些改变。 Git添加。 git commit -m“我做了某事”

软，混合和硬是一种让你放弃从3到1的操作的方法。

柔软的“假装”从未见过你有没有犯过错。 混“假装”从来没见过你有没有git加。 硬“假装”从来没有看到你做了文件更改。

-混合vs -软vs -硬:

--mixed:

   Delete changes from the local repository and staging area.

   It won't touch the working directory.

   Possible to revert back changes by using the following commands.

     - git add

     - git commit

   Working tree won't be clean.

--soft:

    Deleted changes only from the local repository.

    It won't touch the staging area and working directory.

    Possible to revert back changes by using the following command.

     - git commit.

    Working tree won't be clean

--hard:

    Deleted changes from everywhere.

    Not possible to revert changes.

    The working tree will be clean.

注意:如果提交被确认到本地存储库并放弃这些提交，我们可以使用:

 `git reset command`.

但是如果提交被确认到远程存储库，那么不建议使用reset命令，我们必须使用revert命令来丢弃远程提交。