Reflog for finding lost commits in Git - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What does the command git reflog show?

You run git reflog in your repository. What output do you expect to see?

Git

git reflog

A A list of recent HEAD positions with commit hashes and messages.

B A list of all tags in the repository.

C The current status of files in the working directory.

D A list of all branches and their remote tracking status.

💡 Hint

Think about what 'reflog' tracks in Git.

git reflog shows a history of where HEAD has pointed recently, including commits you may have lost track of.

💻 Command Output

intermediate

What is the output of git reflog show HEAD@{2}?

Assuming your reflog has at least 3 entries, what does this command display?

Git

git reflog show HEAD@{2}

A The commit details of the third most recent HEAD position.

B The current commit hash and message.

C An error saying the reflog entry does not exist.

D A list of all commits in the repository.

💡 Hint

HEAD@{n} refers to the nth previous position of HEAD.

HEAD@{2} means the HEAD position two moves ago, so this shows that commit's details.

🔀 Workflow

advanced

How to recover a lost commit using reflog?

You accidentally reset your branch and lost a commit. Which sequence of commands correctly recovers the lost commit using reflog?

A 1,3,2,4

B 1,2,3,4

C 2,1,3,4

D 1,4,3,2

💡 Hint

First find the commit, then create a branch from it.

First, use git reflog to find the lost commit hash. Then checkout that commit, create a new branch, and switch to it.

❓ Troubleshoot

advanced

Why does git reflog not show a lost commit?

You lost a commit but git reflog does not list it. What is the most likely reason?

A The commit is hidden because the branch was deleted.

B The commit was never created in the repository.

C The reflog only shows remote branch history, not local commits.

D The reflog expired or was cleaned and no longer tracks that commit.

💡 Hint

Reflog entries expire after some time or cleanup.

Reflog entries expire after a default time (usually 90 days) or can be cleaned manually, so old commits may disappear from reflog.

✅ Best Practice

expert

What is the best practice to avoid losing commits that reflog might not recover?

Which option is the best practice to ensure commits are not lost even if reflog expires or is cleaned?

A Use <code>git reset --hard</code> frequently to clean history.

B Rely solely on reflog to find lost commits when needed.

C Regularly push commits to a remote repository to back them up.

D Delete branches immediately after merging to keep history clean.

💡 Hint

Think about how to keep commits safe beyond local history.

Pushing commits to a remote repository backs them up safely, preventing loss even if local reflog is cleaned.