Branches – Full Stack JavaScript Developer

So far all your commits live on a single line of history called main (older repos used master — same idea). Branches let you split off a separate line of work without affecting main.

Why Branches?

Imagine you're building a blog and main works perfectly. You want to try a dark-mode redesign but you're not sure it'll look good. Instead of risking main, you create a branch:

main — stays stable, always deployable
dark-mode — your experiment; if it fails, delete the branch and main is untouched

Branches are cheap in Git. Creating one takes milliseconds. Professional teams use them constantly.

See Your Current Branch

git branch

Output:

* main

The asterisk shows which branch you're on.

Create and Switch to a Branch

git switch -c dark-mode

-c means "create." You're now on dark-mode. Any commits you make go here, not on main.

Older tutorials use git checkout -b dark-mode — same result, but git switch is clearer for beginners.

Work on the Branch

Edit your CSS as if you're building dark mode:

body {
  background-color: #1a1a2e;
  color: #eaeaea;
  font-family: sans-serif;
  max-width: 600px;
  margin: 0 auto;
  padding: 2rem;
}

h1 {
  color: #7c3aed;
}

Commit on the branch:

git add styles.css
git commit -m "Add dark mode styles"
git log --oneline

Switch Back to Main

git switch main

Open styles.css — your dark mode changes are gone from the working files. They still exist on the dark-mode branch, safe and sound.

git switch dark-mode

Dark mode is back. Branches keep versions of your project separate.

Merge a Branch

Happy with dark mode? Bring it into main:

git switch main
git merge dark-mode

Git combines the commits from dark-mode into main. Your dark styles now live on main too.

git log --oneline

You'll see commits from both branches in main's history.

Delete a Branch

After merging, the branch has served its purpose:

git branch -d dark-mode

If you abandon an experiment without merging:

git branch -D experimental-feature

Capital -D forces deletion even if changes weren't merged — use when you're sure you don't want that work.

Branch Naming Tips

Use short, descriptive names:

fix-footer-link
add-contact-page
dark-mode

Avoid spaces. Use hyphens or slashes: feature/dark-mode.

Typical Team Flow

Create a branch for each feature or bug fix.
Commit on that branch.
Open a pull request on GitHub (next lesson) for review.
Merge into main when approved.
Delete the branch.

You'll use branches every day once you're collaborating. For solo projects they're still useful — main stays clean while you experiment freely.

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