HEAD pointer concept in Git - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the command to show the current branch where HEAD is pointing.

Git

git [1]

Drag options to blanks, or click blank then click option'

Abranch

Bstatus

Ccommit

Dlog

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'git status' which shows changes but not the branch list.

Using 'git commit' which creates a commit, not shows branches.

The git branch command lists branches and highlights the current branch where HEAD points.

2fill in blank

medium

Complete the command to move HEAD to a specific commit hash.

Git

git checkout [1]

Drag options to blanks, or click blank then click option'

Abranch_name

Btag_name

Cremote_name

Dcommit_hash

Attempts:

3 left

💡 Hint

Common Mistakes

Using a branch name instead of a commit hash when wanting detached HEAD.

Using remote or tag names which are not commit hashes.

The git checkout command with a commit hash moves HEAD to that commit in detached mode.

3fill in blank

hard

Fix the error in the command to reset HEAD to the previous commit.

Git

git reset [1] HEAD~1

Drag options to blanks, or click blank then click option'

A--merge

B--soft

C--hard

D--keep

Attempts:

3 left

💡 Hint

Common Mistakes

Using --hard which discards changes.

Using --merge or --keep which are for other reset behaviors.

The --soft option moves HEAD to the previous commit but keeps changes staged.

4fill in blank

hard

Fill both blanks to create a new branch and move HEAD to it.

Git

git [1] -b [2]

Drag options to blanks, or click blank then click option'

Acheckout

Bbranch

Cnew-feature

Dmaster

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'git branch -b' which is invalid syntax.

Using 'master' as the new branch name when the task expects 'new-feature'.

The command git checkout -b new-feature creates and switches HEAD to the new branch.

5fill in blank

hard

Fill all three blanks to show the commit where HEAD currently points.

Git

git [1] -[2] 1 [3]

Drag options to blanks, or click blank then click option'

Alog

Bn

CHEAD

Dbranch

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'git branch' which lists branches, not commits.

Omitting the '-n' option to limit commits.

The command git log -n 1 HEAD shows the latest commit where HEAD points.

Practice

1. What does the HEAD pointer in Git represent?

easy

A. The current commit your working directory is based on

B. The remote repository URL

C. The list of all branches

D. The stash of uncommitted changes

Solution

1. Step 1: Understand the role of HEAD in Git

   HEAD points to the current commit that your working directory reflects.

2. Step 2: Differentiate HEAD from other Git concepts

   HEAD is not related to remote URLs, branch lists, or stash; it tracks your current position in history.

3. Final Answer:

   The current commit your working directory is based on -> Option A

4. Quick Check:

   HEAD = current commit [OK]

Hint: HEAD always points to your current commit position [OK]

Common Mistakes:

• Confusing HEAD with remote repository
• Thinking HEAD lists branches
• Assuming HEAD stores uncommitted changes

2. Which Git command correctly moves the HEAD pointer to the branch named feature?

easy

A. git merge feature

B. git checkout feature

C. git push feature

D. git commit feature

Solution

1. Step 1: Identify the command to switch branches

   The git checkout command moves HEAD to the specified branch.

2. Step 2: Confirm other commands do not move HEAD

   git commit creates commits, git push uploads changes, git merge combines branches but does not move HEAD directly.

3. Final Answer:

   git checkout feature -> Option B

4. Quick Check:

   Switch branch = git checkout [OK]

Hint: Use git checkout to move HEAD to another branch [OK]

Common Mistakes:

• Using git commit to switch branches
• Confusing git push with moving HEAD
• Thinking git merge moves HEAD

3. Given the following commands run in order:

git checkout main
# HEAD points to main branch

git checkout -b new-feature
# Create and switch to new-feature branch

git commit -m "Add feature"
# Commit on new-feature branch

What does HEAD point to after these commands?

medium

A. No commit, HEAD is detached

B. The latest commit on the main branch

C. The initial commit of the repository

D. The latest commit on the new-feature branch

Solution

1. Step 1: Track HEAD movement through commands

   Initially, HEAD points to main branch. Then git checkout -b new-feature creates and switches HEAD to new-feature branch.

2. Step 2: Commit on new-feature updates HEAD

   The commit adds a new commit on new-feature branch, so HEAD points to this latest commit.

3. Final Answer:

   The latest commit on the new-feature branch -> Option D

4. Quick Check:

   HEAD follows current branch's latest commit [OK]

Hint: HEAD moves with branch switch and points to latest commit [OK]

Common Mistakes:

• Assuming HEAD stays on main after branch creation
• Thinking HEAD detaches after commit
• Confusing initial commit with latest commit

4. You ran git checkout HEAD~1 but now your prompt shows (HEAD detached at ...). What is the problem?

medium

A. HEAD is detached because you checked out a commit, not a branch

B. HEAD is detached because you deleted the branch

C. HEAD is detached because the repository is corrupted

D. HEAD is detached because you pushed to remote

Solution

1. Step 1: Understand what git checkout HEAD~1 does

   This command checks out the commit before the current HEAD, not a branch.

2. Step 2: Explain detached HEAD state

   Checking out a commit directly detaches HEAD, meaning it points to a commit, not a branch.

3. Final Answer:

   HEAD is detached because you checked out a commit, not a branch -> Option A

4. Quick Check:

   Detached HEAD = checked out commit, not branch [OK]

Hint: Detached HEAD means checked out a commit, not a branch [OK]

Common Mistakes:

• Thinking detached HEAD means repo corruption
• Assuming branch was deleted
• Confusing push with HEAD detachment

5. You want to move HEAD back two commits on the current branch but keep your working files unchanged. Which command should you use?

hard

A. git reset --hard HEAD~2

B. git checkout HEAD~2

C. git reset --soft HEAD~2

D. git revert HEAD~2

Solution

1. Step 1: Understand reset options

   git reset --soft moves HEAD and branch pointer but keeps working directory unchanged.

2. Step 2: Compare other options

   --hard resets files too, checkout detaches HEAD, revert creates a new commit undoing changes.

3. Final Answer:

   git reset --soft HEAD~2 -> Option C

4. Quick Check:

   Reset soft moves HEAD, keeps files [OK]

Hint: Use git reset --soft to move HEAD without changing files [OK]

Common Mistakes:

• Using --hard and losing changes
• Using checkout and detaching HEAD
• Using revert which creates new commits