Why merging combines work in Git - See It in Action

Why merging combines work

📖 Scenario: You are working on a team project using Git. Two team members have made changes in separate branches. You want to combine their work into the main branch so everyone has the latest updates.

🎯 Goal: Learn how to merge two branches in Git to combine work from different team members into one branch.

📋 What You'll Learn

Create a new branch called feature from main

Make a change in the feature branch

Switch back to main and make a different change

Merge the feature branch into main

Show the combined changes after merging

💡 Why This Matters

🌍 Real World

Teams use Git merging to combine work from different developers safely and keep the project up to date.

💼 Career

Understanding merging is essential for collaboration in software development and DevOps roles.

1

Create a new branch and add a file

Create a new branch called feature from main and create a file named file.txt with the content Feature work in the feature branch.

Git

# Create and switch to the feature branch
# Create file.txt with content 'Feature work'
# Your code here

Hint

Use git checkout -b feature to create and switch to the new branch. Use echo to create the file and git commit to save changes.

2

Switch to main and add a different file

Switch back to the main branch and create a file named file.txt with the content Main work in the main branch.

Git

git checkout -b feature
echo 'Feature work' > file.txt
git add file.txt
git commit -m "Add feature work file"

# Switch to main branch
# Create file.txt with content 'Main work'
# Your code here

Hint

Use git checkout main to switch back. Then create and commit the new file with different content.

3

Merge feature branch into main

While on the main branch, merge the feature branch into main using the git merge feature command.

Git

git checkout -b feature
echo 'Feature work' > file.txt
git add file.txt
git commit -m "Add feature work file"
git checkout main
echo 'Main work' > file.txt
git add file.txt
git commit -m "Add main work file"

# Merge feature branch into main
# Your code here

Hint

Use git merge feature while on main to combine the changes.

4

Show the combined file content after merge

Use the cat file.txt command to display the content of file.txt after the merge.

Git

git checkout -b feature
echo 'Feature work' > file.txt
git add file.txt
git commit -m "Add feature work file"
git checkout main
echo 'Main work' > file.txt
git add file.txt
git commit -m "Add main work file"
git merge feature

# Show the content of file.txt
# Your code here

Hint

Use cat file.txt to see the combined content after merging.

Practice

1. What does the git merge command do in a project?

easy

A. It creates a new branch from the current branch.

B. It deletes a branch permanently.

C. It combines changes from one branch into another branch.

D. It shows the history of commits in the current branch.

Solution

1. Step 1: Understand the purpose of git merge

   The git merge command is used to combine changes from one branch into another branch.

2. Step 2: Compare with other git commands

   Deleting branches is done with git branch -d, creating branches with git branch, and viewing history with git log. None of these combine work like merge.

3. Final Answer:

   It combines changes from one branch into another branch. -> Option C

4. Quick Check:

   Merge = combine changes [OK]

Hint: Merge means combining work from branches [OK]

Common Mistakes:

• Confusing merge with branch deletion
• Thinking merge creates new branches
• Mixing merge with viewing commit history

2. Which of the following is the correct syntax to merge a branch named feature into your current branch?

easy

A. git merge feature

B. git merge -b feature

C. git merge --create feature

D. git merge -d feature

Solution

1. Step 1: Recall the git merge syntax

   The correct syntax to merge a branch is git merge <branch-name>. So for branch 'feature', it is git merge feature.

2. Step 2: Identify incorrect options

   Options with flags like -b, --create, or -d are not valid for merging branches.

3. Final Answer:

   git merge feature -> Option A

4. Quick Check:

   Merge syntax = git merge branch-name [OK]

Hint: Use 'git merge branch-name' to combine branches [OK]

Common Mistakes:

• Adding wrong flags like -b or -d
• Confusing merge with branch creation
• Using incorrect command order

3. Given the following commands run in order:

git checkout main
git merge feature

What happens after these commands?

medium

A. The 'feature' branch is deleted.

B. The 'main' branch is reset to the state of 'feature'.

C. A new branch named 'feature' is created.

D. The changes from the 'feature' branch are combined into 'main'.

Solution

1. Step 1: Analyze the commands

   First, git checkout main switches to the 'main' branch. Then, git merge feature merges changes from 'feature' into 'main'.

2. Step 2: Understand the effect of merge

   The merge combines the work from 'feature' into 'main' without deleting or resetting branches.

3. Final Answer:

   The changes from the 'feature' branch are combined into 'main'. -> Option D

4. Quick Check:

   Checkout + merge = combine changes [OK]

Hint: Checkout target branch, then merge source branch [OK]

Common Mistakes:

• Thinking merge deletes branches
• Confusing merge with reset
• Assuming merge creates new branches

4. You ran git merge feature but got a conflict error. What should you do next?

medium

A. Delete the 'feature' branch to fix the conflict.

B. Manually resolve conflicts in files, then commit the merge.

C. Run git merge --abort and ignore the changes.

D. Run git reset --hard to force merge.

Solution

1. Step 1: Understand merge conflicts

   When a conflict occurs, Git stops the merge and asks you to fix conflicting files manually.

2. Step 2: Resolve conflicts and complete merge

   You must open the conflicting files, fix the differences, then commit the merge to finish combining work.

3. Final Answer:

   Manually resolve conflicts in files, then commit the merge. -> Option B

4. Quick Check:

   Conflicts require manual fix + commit [OK]

Hint: Fix conflicts manually, then commit merge [OK]

Common Mistakes:

• Deleting branches to fix conflicts
• Aborting merge without resolving
• Using reset to force merge ignoring conflicts

5. You have two branches: main and feature. Both have new commits. You want to combine them so main has all changes, but keep the history clear. Which sequence is best?

hard

A. Checkout main, run git merge feature, then push main.

B. Checkout feature, run git merge main, then delete main.

C. Delete feature, then copy files manually to main.

D. Checkout main, run git rebase feature, then push main.

Solution

1. Step 1: Identify the goal

   You want main to have all changes from both branches and keep history clear.

2. Step 2: Choose the correct merge approach

   Checking out main and merging feature combines work properly and keeps history intact. Rebasing rewrites history and is more complex.

3. Final Answer:

   Checkout main, run git merge feature, then push main. -> Option A

4. Quick Check:

   Merge feature into main to combine work [OK]

Hint: Merge feature into main branch to combine work safely [OK]

Common Mistakes:

• Merging main into feature instead of the reverse
• Deleting branches before merging
• Using rebase without understanding history rewrite