Git 104: branch ช่วยให้ทดลองอย่างปลอดภัยGit 104: branches let you experiment safely

A branch is a separate line of work.

Use a branch when a change should be isolated until you inspect it.

See your current branch

Run:

git branch

The current branch has a marker next to it.

Many projects use main as the default branch.

Create and switch to a branch

Create a branch for a small README improvement:

git switch -c docs-add-learning-goal

Read this as:

Create a branch and switch to it.

Now edit README.md:

## Learning goal

Practice checking status and diff before saving work.

Commit the change:

git status
git diff
git add README.md
git commit -m "docs: add learning goal"

Switch back to main

Run:

git switch main

Open the file again. The learning goal may disappear because that change exists on your branch, not on main yet.

That is the point. Branches keep work isolated.

Merge the branch

When the branch is ready:

git merge docs-add-learning-goal

Now the change becomes part of the current branch.

Check:

git log --oneline --graph --all -5
git status

Delete a finished local branch

After the branch is merged:

git branch -d docs-add-learning-goal

This deletes the branch name, not the commit history that was merged.

Branch naming habits

Use names that make the purpose clear:

docs-add-learning-goal
fix-login-redirect
experiment-new-layout

Avoid:

stuff
try
new

Your future self and reviewers need context.

When not to switch

Do not switch branches with messy uncommitted work unless you know what will happen.

Before switching:

git status

If you have uncommitted changes, decide:

• commit them
• discard them if they are truly not needed
• stash them if you know how stash works

For beginners, a clean working tree is the safest branch-switching state.

Practice: branch checklist

Fill this before starting a branch:

Branch name:

Goal:

Files I expect to change:

How I will verify:

What should stay untouched:

That last line matters when working with AI agents. It tells the agent what not to edit.

Next: Git 105 - remotes, pull, push, and GitHub.