Three-way merge in Git - Mini Project: Build & Apply

Three-way Merge with Git

📖 Scenario: You are working on a team project using Git. Two team members have made changes to the same file in different branches. You need to merge these branches using a three-way merge to combine their changes safely.

🎯 Goal: Learn how to perform a three-way merge in Git to combine changes from two branches into one, resolving conflicts if they appear.

📋 What You'll Learn

Create a Git repository with an initial file

Create and switch to a new branch

Make changes in both branches

Perform a three-way merge to combine changes

💡 Why This Matters

🌍 Real World

Teams use three-way merges daily to combine code changes from multiple developers safely.

💼 Career

Understanding three-way merges is essential for software developers, DevOps engineers, and anyone collaborating on code using Git.

1

Initialize Git repository and create initial file

Run git init to create a new Git repository. Then create a file named project.txt with the content Hello World. Add and commit this file with the message Initial commit using git add project.txt and git commit -m "Initial commit".

Git

# Run git init and create project.txt with 'Hello World'
# Add and commit the file
# Your code here

Need a hint?

Use git init to start the repo. Use echo to create the file. Then add and commit.

2

Create and switch to a new branch

Create a new branch called feature using git branch feature. Then switch to this branch using git checkout feature.

Git

git init

echo "Hello World" > project.txt

git add project.txt

git commit -m "Initial commit"

# Create and switch to branch 'feature'
# Your code here

Need a hint?

Use git branch feature to create and git checkout feature to switch branches.

3

Make changes in both branches

On the feature branch, change project.txt content to Hello from feature branch and commit with message Feature update. Then switch back to main branch using git checkout main, change project.txt content to Hello from main branch and commit with message Main update.

Git

git init

echo "Hello World" > project.txt

git add project.txt

git commit -m "Initial commit"

git branch feature

git checkout feature

# Change project.txt on feature branch and commit
# Switch to main branch
# Change project.txt on main branch and commit
# Your code here

Need a hint?

Use echo to overwrite the file content. Commit changes on each branch separately.

4

Perform a three-way merge

Merge the feature branch into main using git merge feature. If there are conflicts, resolve them by editing project.txt to contain Hello from both branches, then add and commit the merge with message Merge feature branch. Finally, print the content of project.txt using cat project.txt.

Git

git init

echo "Hello World" > project.txt

git add project.txt

git commit -m "Initial commit"

git branch feature

git checkout feature

echo "Hello from feature branch" > project.txt

git add project.txt

git commit -m "Feature update"

git checkout main

echo "Hello from main branch" > project.txt

git add project.txt

git commit -m "Main update"

# Merge feature branch into main
# If conflict, edit project.txt to 'Hello from both branches'
# Add and commit the merge
# Print project.txt content
# Your code here

Need a hint?

Use git merge feature. If conflict occurs, fix the file manually, then add and commit.