Git · Lesson 3 of 6

Branches & merging

Creating branches, switching, merging and resolving conflicts.

A branch is an independent line of work. Build a feature on its own branch, keep main stable, and merge when it's ready.

git switch -c feature/login — create and move to a new branch.
git branch — list branches (the * marks the current one).
git merge feature/login — bring that branch's commits into the current branch.

Merge conflicts

If both branches changed the same lines, Git stops and marks the file with <<<<<<<, ======= and >>>>>>>. Edit the file to the correct final version, remove the markers, then git add and git commit.

Example in the terminal

Run these on your own computer

$ git switch -c feature/salary-filter
Switched to a new branch 'feature/salary-filter'

$ git add filter.js
$ git commit -m "Add salary range filter"

$ git switch main
$ git merge feature/salary-filter
Updating 3f2c1aa..8b41d07
Fast-forward
 filter.js | 24 ++++++++++++++++++++++++

$ git branch -d feature/salary-filter
Deleted branch feature/salary-filter

Lines starting with $ are commands you type; the rest is what Git prints. Names and URLs are examples.

Key points

One branch per feature or fix.
Merge back into main when done.
Conflicts = same lines changed; edit, add, commit.

Quick check

Which command creates and switches to a new branch?

git branch -m git switch -c name git merge name git checkout --orphan

Practice task

Make a branch, change one line of README.md there, change the same line differently on main, merge, and resolve the conflict.

Interview corner

Merge vs rebase?

Merge joins histories with a merge commit and keeps the true timeline. Rebase replays your commits on top of another branch for a straight history — but don't rebase commits others already pulled.

What is a fast-forward merge?

When main has no new commits since the branch started, Git just moves main's pointer forward — no merge commit is needed.