Branch Basics

Working Code

Example 1: Creating and switching branches

Start with a repository that has a commit:

git init
echo "# Project" > README.md
git add README.md
git commit -m "feat: initial commit"

Check the current branch:

git branch

Output:

* main

The * marks the current branch.

Create a new branch:

git branch feature-login
git branch

Output:

  feature-login
* main

The branch is created but you're still on main. Switch to it:

git checkout feature-login
git branch

Output:

* feature-login
  main

Example 2: Working on a branch

Add a file on feature-login:

echo "// Login feature" > login.js
git add login.js
git commit -m "feat: add login feature"

Switch back to main and login.js is gone:

git checkout main
ls

Output:

README.md

Branches are completely independent workspaces.

Example 3: Visualizing branch history

git log --oneline --graph --all

Output:

* a1b2c3d (feature-login) feat: add login feature
* e4f5g6h (HEAD -> main) feat: initial commit

--all shows commits from all branches. --graph draws the structure in ASCII.

Try It Yourself

Create and switch in one step

# git branch + git checkout in one command
git checkout -b feature-signup
git branch

Output:

  feature-login
* feature-signup
  main

Work on multiple branches:

# Work on feature-signup
echo "// Signup" > signup.js
git add signup.js
git commit -m "feat: add signup page"

# Switch to feature-login
git checkout feature-login

# Update login.js
echo "// Login complete" >> login.js
git add login.js
git commit -m "feat: complete login form"

Compare branches:

git log --oneline --graph --all

Output:

* f7g8h9i (feature-signup) feat: add signup page
| * j0k1l2m (feature-login) feat: complete login form
| * a1b2c3d feat: add login feature
|/
* e4f5g6h (HEAD -> main) feat: initial commit

The branching structure is clearly visible.

Deleting branches

# Switch to main first, then delete
git checkout main
git branch -d feature-signup

Output:

Deleted branch feature-signup (was f7g8h9i).

Deleting an unmerged branch:

git branch -d feature-unmerged
# error: The branch 'feature-unmerged' is not fully merged.

# Force delete (use with caution!)
git branch -D feature-unmerged

"Why?" -- Why branches matter

Without branches:

• You're stuck when a critical bug fix is needed while developing a new feature
• Multiple people editing the same file leads to conflicts
• Experimental changes risk breaking existing code

Branches provide independent workspaces:

main (stable, deployable)
|-- feature/login     <- Login feature development
|-- feature/signup    <- Signup feature development
+-- fix/typo         <- Typo fix

Branches as pointers

A branch is just a pointer (label) to a specific commit. Creating a branch simply creates a new pointer, making it extremely lightweight.

Commit A <- Commit B <- Commit C
                            ^
                           main (pointer)

Commit A <- Commit B <- Commit C <- Commit D (feature work)
                            ^                    ^
                           main          feature-login (new pointer)

HEAD points to the branch/commit you currently have checked out:

Commit C <- Commit D
                ^
        feature-login <- HEAD

Common Mistakes

Mistake 1: Switching branches without committing

echo "Work in progress" > file.txt

git checkout main  # Warning or changes may carry over

# Safe approach: commit or stash before switching
git add file.txt
git commit -m "wip: save work in progress"
git checkout main

Or:

git stash          # Temporarily save (covered in Lesson 8)
git checkout main

Mistake 2: Developing features directly on main

# Bad habit
git checkout main
echo "New feature" > feature.js
git commit -m "feat: new feature"   # Committed directly to main

# Good habit
git checkout -b feature/new-feature
echo "New feature" > feature.js
git commit -m "feat: new feature"   # Committed to a feature branch

Mistake 3: Spaces in branch names

# Wrong
git checkout -b "my feature branch"

# Correct: use hyphens or slashes
git checkout -b feature/my-feature
git checkout -b my-feature-branch

Deep Dive

# Switch branches
git switch feature-login

# Create and switch in one step
git switch -c feature-new

# Return to main
git switch main

feature/user-login
feature/payment-integration
fix/cart-item-count-bug
hotfix/security-patch

# Detailed graph options
git log --oneline --graph --all --decorate

# Include dates
git log --oneline --format="%h %ai %s" --all

# Register as an alias for convenience
git config --global alias.lg "log --oneline --graph --all --decorate"
git lg   # Now you can use the short form