# git branch, checkout & merge

## Goal
Create branches, switch between them, and merge changes.

## Create and List Branches
```bash
cd ~/lab-git-essentials/my-first-repo
git branch
git checkout -b feature/intro
git branch
```

## Add Work on the Feature Branch
```bash
echo "Feature text" >> README.md
git add README.md
git commit -m "Add feature text to README"
```

## Switch Back to Main and Merge
```bash
git checkout -b main 2>/dev/null || true
git checkout main
git merge feature/intro
```

## Create a Merge Conflict (Optional, for practice)
```bash
# On main, change the same line differently
sed -i '1s/.*/# My First Repo (main)/' README.md
git add README.md
git commit -m "Tweak README title on main"

# On feature branch, make a conflicting change
git checkout feature/intro
sed -i '1s/.*/# My First Repo (feature)/' README.md
git add README.md
git commit -m "Tweak README title on feature"

# Merge and resolve
git checkout main
git merge feature/intro
# Open README.md, resolve conflict markers <<<<<<<, =======, >>>>>>>
git add README.md
git commit   # finalizes the merge
```

## Outcome
You can branch, switch branches with `git checkout`, and merge changes, including resolving conflicts.