Git Branches

A branch is just a movable pointer to a commit. Committing moves the checked-out branch forward, so work on separate branches doesn’t interfere until you combine it.

Working with branches

Command	Effect
git switch -c develop	Creates develop at the current commit and switches to it.
git switch main	Switches to an existing branch.
git switch -	Switches back to the previous branch.
git branch -a	Lists local and remote-tracking branches.
git branch -vv	Shows which remote branch each local branch tracks, and how far ahead or behind it is.
git branch -m old new	Renames a branch.
git branch -d develop	Deletes a branch that is merged.
git branch -D develop	Deletes a branch even if it isn’t merged.
git push origin --delete develop	Deletes the branch on the remote.

git checkout <branch> and git checkout -b <branch> still work; switch is the newer command that only handles branches.

Combining branches

All three ways end with the changes of feature on main; they differ in what the history looks like.

Merge

Keeps both lines of history and joins them with a merge commit.

gitGraph
  commit id: "A"
  commit id: "B"
  branch feature
  commit id: "C"
  commit id: "D"
  checkout main
  commit id: "E"
  merge feature id: "merge"

git switch main
git merge feature

Rebase

Replays the feature commits on top of main as new commits (C', D'), giving a straight line. main can then fast-forward without a merge commit.

gitGraph
  commit id: "A"
  commit id: "B"
  commit id: "E"
  branch feature
  commit id: "C'"
  commit id: "D'"

git switch feature
git rebase main
git switch main
git merge --ff-only feature

Squash merge

Combines all feature commits into a single new commit on main.

gitGraph
  commit id: "A"
  commit id: "B"
  commit id: "E"
  commit id: "C+D"

git switch main
git merge --squash feature
git commit

Tip

After a squash merge, git branch -d feature refuses because the original commits aren’t on main. Use -D once you have checked that the changes landed.