Reading conflict markers in Git - Commands & Configuration

Introduction

When two people change the same part of a file in different ways, Git cannot decide which change to keep. It marks the file with conflict markers so you can see both versions and fix the conflict.

When you pull changes from a shared repository and your local file has conflicting edits.

When you merge two branches that changed the same lines differently.

When you rebase your branch onto another branch and conflicts appear.

When you cherry-pick a commit that conflicts with your current code.

When you resolve conflicts manually before completing a merge or rebase.

Commands

This command tries to merge the 'feature-branch' into your current branch. If there are conflicting changes, Git will stop and mark the conflicts in the files.

Terminal

git merge feature-branch

Expected Output

Auto-merging example.txt

CONFLICT (content): Merge conflict in example.txt

Automatic merge failed; fix conflicts and then commit the result.

This command shows the content of the file with conflict markers so you can see the conflicting parts and decide how to fix them.

Terminal

cat example.txt

Expected Output

<<<<<<< HEAD

This is the original line from your branch.

=======

This is the conflicting line from feature-branch.

>>>>>>> feature-branch

This command shows which files have conflicts and need to be fixed before you can complete the merge.

Terminal

git status

Expected Output

On branch main

You have unmerged paths.

  (fix conflicts and run "git commit")



Unmerged paths:

  (use "git add <file>..." to mark resolution)



	both modified:   example.txt



no changes added to commit (use "git add" and/or "git commit -a")

Key Concept

If you remember nothing else from this pattern, remember: conflict markers show exactly where Git found different changes so you can choose which to keep.

Common Mistakes

Ignoring conflict markers and committing the file as is.

This leaves the conflict markers in the code, which breaks the program and confuses others.

Manually edit the file to remove conflict markers and keep the correct code, then add and commit.

Deleting the entire conflicting section without reviewing both versions.

You might lose important changes from either branch.

Carefully compare both sides of the conflict markers and combine or choose the correct changes.

Not running 'git add' after fixing conflicts before committing.

Git will not know the conflict is resolved and will prevent the commit.

After fixing conflicts, run 'git add <file>' to mark the conflict as resolved.

Summary

Run 'git merge' to combine branches; conflicts will stop the merge and mark files.

Open files with conflicts to see markers showing both versions.

Fix conflicts by editing, then add and commit to complete the merge.

Practice

1. What do conflict markers in a Git file indicate?

easy

A. They show where changes from different branches clash in the file.

B. They mark lines that are deleted permanently.

C. They highlight syntax errors in the code.

D. They indicate lines that are ignored by Git.

Solution

1. Step 1: Understand the purpose of conflict markers

   Conflict markers appear when Git cannot automatically merge changes from different branches.

2. Step 2: Identify what conflict markers show

   They highlight the exact lines where changes from two sources conflict, so you can decide how to fix them.

3. Final Answer:

   They show where changes from different branches clash in the file. -> Option A

4. Quick Check:

   Conflict markers = show clashes [OK]

Hint: Conflict markers always show merge clashes in files [OK]

Common Mistakes:

• Thinking conflict markers show deleted lines
• Confusing conflict markers with syntax errors
• Believing conflict markers mark ignored lines

2. Which of the following is the correct way conflict markers appear in a Git file?

easy

A. >>>>>> HEAD
Your changes here
======
Incoming changes here
<<<<<<< branch-name

B. <<<<<<< HEAD
Your changes here
=======
Incoming changes here
>>>>>>> branch-name

C. <<<<<<< branch-name
Incoming changes here
=======
Your changes here
>>>>>>> HEAD

D. ======
Your changes here
<<<<<<< HEAD
Incoming changes here
>>>>>>> branch-name

Solution

1. Step 1: Recall the standard conflict marker format

   Git uses <<<<<<< HEAD to start your changes, ======= to separate, and >>>>>>> branch-name to end.

2. Step 2: Match the correct sequence

   <<<<<<< HEAD Your changes here ======= Incoming changes here >>>>>>> branch-name matches this exact format with your changes first, separator, then incoming changes.

3. Final Answer:

   <<<<<<< HEAD Your changes here ======= Incoming changes here >>>>>>> branch-name -> Option B

4. Quick Check:

   Conflict markers start with <<<<<<< HEAD [OK]

Hint: Conflict markers start with <<<<<<< HEAD and end with >>>>>>> branch-name [OK]

Common Mistakes:

• Swapping HEAD and branch-name positions
• Using wrong number of < or > symbols
• Mixing up the order of your and incoming changes

3. Given this conflict marker snippet in a file:

<<<<<<< HEAD
int x = 5;
=======
int x = 10;
>>>>>>> feature-branch

What will be the value of x after you manually choose the incoming change and save?

medium

A. 15

B. 5

C. 10

D. Conflict remains, no value assigned

Solution

1. Step 1: Identify the incoming change section

   The incoming change is after the ======= marker, which is int x = 10;.

2. Step 2: Understand manual conflict resolution

   Choosing the incoming change means keeping int x = 10; and removing conflict markers.

3. Final Answer:

   10 -> Option C

4. Quick Check:

   Incoming change value = 10 [OK]

Hint: Incoming changes are after ======= marker [OK]

Common Mistakes:

• Choosing the code before ======= instead of after
• Leaving conflict markers in the file
• Assuming both values apply simultaneously

4. You see this conflict marker in your file:

<<<<<<< HEAD
console.log('Hello');
=======
console.log('Hi');
>>>>>>> update-branch

After editing, you accidentally leave the conflict markers in the file and commit. What problem will this cause?

medium

A. The conflict markers will be ignored and code runs fine.

B. Git will automatically fix the conflict on next pull.

C. Git will delete the file on next merge.

D. The code will have syntax errors and may not run.

Solution

1. Step 1: Understand what conflict markers are

   Conflict markers are not valid code; they are special symbols for humans to resolve conflicts.

2. Step 2: Effect of leaving markers in code

   If left in the file, the code will have syntax errors and likely fail to run or compile.

3. Final Answer:

   The code will have syntax errors and may not run. -> Option D

4. Quick Check:

   Leaving markers = syntax errors [OK]

Hint: Remove conflict markers before committing to avoid errors [OK]

Common Mistakes:

• Assuming Git fixes conflicts automatically after commit
• Thinking conflict markers are comments
• Believing code runs fine with markers present

5. You have this conflict in a file:

<<<<<<< HEAD
function greet() {
  return 'Hello';
}
=======
function greet() {
  return 'Hi';
}
>>>>>>> feature

You want to combine both greetings so the function returns both messages separated by a comma. How should you edit the file to resolve the conflict correctly?

hard

A. Replace the conflict markers with:
function greet() {
return 'Hello, Hi';
}

B. Keep only the HEAD version:
function greet() {
return 'Hello';
}

C. Keep only the feature version:
function greet() {
return 'Hi';
}

D. Leave the conflict markers and both versions as is.

Solution

1. Step 1: Understand the goal to combine greetings

   You want the function to return both messages, so you must merge the changes manually.

2. Step 2: Edit the file by removing conflict markers and combining lines

   Replace the conflict markers and both versions with a single function returning 'Hello, Hi'.

3. Final Answer:

   Replace the conflict markers with: function greet() { return 'Hello, Hi'; } -> Option A

4. Quick Check:

   Combine changes by editing and removing markers [OK]

Hint: Edit conflict markers out and combine code as needed before commit [OK]

Common Mistakes:

• Leaving conflict markers in the file
• Choosing only one version without combining
• Not saving changes before committing