Creating and switching branches

branch and switch

Switching is constant in real work: you pause a half-done feature to review a teammate's branch, hop to main for an urgent fix, then come back — often five times before lunch. That daily traffic is why the commands are short. Three cover it:

$ git branch new-sauce      # create a label here (doesn't move you)
$ git switch new-sauce      # move HEAD onto that branch
Switched to branch 'new-sauce'
$ git switch -c quick-idea  # create AND switch, one step
Switched to a new branch 'quick-idea'

git branch with no arguments lists your branches, marking your current one with *:

$ git branch
  main
  new-sauce
* quick-idea

Commits you make now move the quick-idea label forward while main stays planted. When the experiment works, unit 5-3 shows how to bring it home.

(In older tutorials you'll see git checkout new-sauce and git checkout -b quick-idea. Same actions, older command. switch was added because checkout did too many unrelated things.)

What switching does to your files

Switching branches rewrites your working directory to match the snapshot the target branch points to. Files change on disk instantly. Switch to a branch from before a file existed and the file disappears from the folder, switch back and it returns. Nothing is lost, snapshots are permanent, but it surprises everyone the first time.

What about uncommitted changes when you switch? If they'd be overwritten by the target snapshot, Git refuses:

$ git switch main
error: Your local changes to the following files would be overwritten by checkout:
	pancakes.txt
Please commit your changes or stash them before you switch branches.

Git protects you and, as always, names your options: commit the work, or stash it, a tool waiting in lesson 10-1.