🕰️ 版本控制：代码的“时光机”🕰️ Version Control: the Time Machine for Code

上一片里，💻小电脑学会按菜谱一步步做事。可做着做着改坏了，怎么办？这一片请出时光机：版本控制。 Last leaf, 💻 Little Computer learned to follow a recipe step by step. But what if it breaks things halfway? Meet the time machine: version control.

第 1 步：每次改动拍张照Step 1: Snapshot every change

先看时光机长什么样——每次存一个快照。First, what the time machine looks like — one snapshot per save.

时光机：快照1、快照2、改坏了、一键回滚 — 小电脑写完作业 v1，咔嚓拍下快照。接着大胆改：改成一团乱码也不怕，点一下一键回滚，嗖地回到快照那一刻。每个快照，都是一颗“后悔药”。 Little Computer finishes homework v1 — click, snapshot saved. Now edit boldly: even if it becomes total garbage, one tap on restore zooms back to the snapshot moment. Every snapshot is a regret pill.

快照存在哪？小电脑有三个盒子，各管各的。Where do snapshots live? The little computer keeps three boxes, each with its own job.

第 2 步：三个盒子Step 2: The three boxes

Git三区：工作区、暂存区、仓库、commit — 工作区是书桌，正在改的东西摊一桌。暂存区是托盘，挑出“这次要存的”。仓库是保险柜，一记 commit 锁进去，永久保存。commit 信息要写清改了什么：“改了一下”等于没说。 The workspace is the desk — current edits sprawl everywhere. The staging area is the tray — holding what goes into this save. The repository is the safe — one commit locks it in forever. And the commit message must say what changed: “changed stuff” says nothing.

两个人同时改一份作业，不会打起来吗？Two friends editing the same homework at once — won't they collide?

第 3 步：分支与合并Step 3: Branches and merging

分支合并：主分支、新功能、合并 — 小电脑开一条“新功能”分支自己写，朋友在主分支上写，两边互不干扰。写完一合并，谁的活都没丢。把仓库传到 GitHub 上，全世界都能一起来写。 Little Computer opens a “new feature” branch to write alone; its friend writes on the main branch — neither disturbs the other. Merge when done, nobody's work is lost. Push the repository to GitHub and the whole world can write together.

🎮 你来开时光机（30 秒）🎮 Your turn: drive the time machine (30 seconds)

道理讲完了。4 关带小电脑穿越一次：排操作顺序 → 拍快照改坏再回滚 → 挑好信息 → 合分支。Theory done. Time-travel 4 rounds with the little computer: order the moves → snapshot, break, restore → pick the good message → merge branches.

一句话记住它：版本控制 = 给每次改动拍快照，随时一键回滚。 Remember it in one line: version control snapshots every change — restore any moment in one tap.

快照存下过去：改坏不怕，一键回到快照那一刻Snapshots save the past: break things fearlessly, one tap back 三区：工作区 → 暂存区 → 仓库；commit 写清改了什么Three boxes: workspace → staging → repository; commits say what changed 分支让多人并行不打架；传到 GitHub，全世界一起写Branches let many work in parallel; push to GitHub, the world joins in

内容参考 OpenStax 等公开教材，多来源核对 · AI 生成、人工审核 · 发现错误欢迎指正，帮这片叶子长得更好。 Based on OpenStax and other open textbooks, cross-checked across sources · AI-generated, human-reviewed · Spotted a mistake? Tell us — help this leaf grow.