Question 1

What is Git, and what is a Distributed Version Control System (DVCS)?

Accepted Answer

Git is a fast, open-source distributed version control system. In a Distributed Version Control System (DVCS), clients do not just check out the latest snapshot of the files from a central server; they fully mirror the repository, including its entire history, locally. If the server dies, any client repository can be copied back up to the server to restore it.

Question 2

What are the three main states/areas in Git?

Accepted Answer

Git has three main states that your files can reside in:
1. Working Directory: The local area where you create and modify project files.
2. Staging Area (Index): A virtual file that lists changes scheduled to be included in the next commit.
3. Git Repository (.git directory): The metadata database storing the permanent snapshots of your project commits.
Code Example:
# Flow of states:
Working Directory --(git add)--> Staging Area --(git commit)--> Git Repository

Question 3

What is the difference between `git pull` and `git fetch`?

Accepted Answer

`git fetch` contacts the remote repository and downloads all new metadata and commits from the remote branches to your local tracker, but does not merge them into your working files. `git pull` is a combination command that performs a `git fetch` followed by a `git merge`, immediately pulling and merging remote changes into your current active local branch.

Question 4

Explain the difference between `git merge` and `git rebase`.

Accepted Answer

`git merge` takes commits from a branch and merges them into the active branch, creating a new 'merge commit' that ties the history together (preserves original commit chronology but can look cluttered). `git rebase` reapplies the commits of the current branch on top of another branch's commits. It rewrites the commit history to make it completely linear, but changes commit hashes.

Question 5

What is a fast-forward merge?

Accepted Answer

A fast-forward merge occurs when there have been no new commits on the target branch since you created the source branch. Git merges changes simply by moving the branch pointer forward to point to the latest commit of the source branch, without creating a new merge commit.

Question 6

What is `git stash`, and when is it used?

Accepted Answer

`git stash` temporarily saves your uncommitted modifications (both staged and unstaged files) to a stack, restoring your working directory back to a clean state. It is useful when you need to switch branches or perform a hotfix without committing half-finished work.
Code Example:
# Stash modifications
git stash

# Switch branches, do work, switch back...
# Apply stashed modifications and remove from stash list
git stash pop

Question 7

What is the difference between `git reset` and `git revert`?

Accepted Answer

`git reset` moves the current branch pointer backward in history to a specific commit, altering history (dangerous for public shared branches). `git revert` creates a *brand new commit* that applies the exact inverse changes of a targeted commit, undoing changes safely without rewriting history.

Question 8

Explain the differences between `git reset --soft`, `--mixed`, and `--hard`.

Accepted Answer

- `--soft`: Moves the HEAD pointer back to the specified commit. Keeps your working directory and staging index untouched; files appear staged for commit.
- `--mixed` (Default): Moves HEAD and updates the staging area. Keeps your working directory files untouched; modifications appear unstaged.
- `--hard`: Moves HEAD, updates the staging area, and overwrites the working directory. **All uncommitted changes are lost.**
Code Example:
# Revert files back to staging area
git reset --soft HEAD~1

# Discard all changes locally
git reset --hard HEAD~1

Question 9

What is `git cherry-pick`?

Accepted Answer

`git cherry-pick` allows you to select a specific commit from one branch and apply its changes directly onto your current active branch. This is useful when you want to import a specific bug fix without merging the entire history of a dev branch.
Code Example:
git cherry-pick <commit-hash>

Question 10

What is `git reflog`?

Accepted Answer

`git reflog` (reference log) keeps track of every single update made to the local branch tips and HEAD pointer in your repository, including commits, checkout branch switches, rebases, and resets. It is the ultimate recovery tool, allowing you to locate and restore commits that have been deleted or lost due to hard resets.

Question 11

What is a merge conflict, and how do you resolve it?

Accepted Answer

A merge conflict occurs when two branches make differing edits to the same line(s) of a file, or when a file is deleted in one branch but edited in another. Git cannot auto-merge and pauses. You resolve conflicts by opening the file, selecting the desired code block (between `<<<<<<< HEAD` and `>>>>>>>`), saving, running `git add` to mark resolved, and finishing with `git commit`.

Question 12

What is a Git commit hash (SHA-1)?

Accepted Answer

In Git, every commit is identified by a unique 40-character cryptographic SHA-1 hash. This hash is calculated based on the contents of the files, the directory structure, the parent commit's hash, the commit message, and the author metadata. This guarantees repository integrity.

Question 13

Explain Git hooks.

Accepted Answer

Git hooks are custom scripts that run automatically before or after specific Git events, such as committing, pushing, or merging. They reside in `.git/hooks/`. For example, a `pre-commit` hook is commonly used to run linters, tests, or check code formatting before allowing a commit to be created.

Question 14

What is the purpose of the `.gitignore` file?

Accepted Answer

The `.gitignore` file specifies untracked files and directories that Git should ignore. Files like compile outputs (e.g. `node_modules/`, `build/`), environment configs containing credentials (`.env`), or OS-specific cache files (`.DS_Store`) should be listed here to prevent committing them.

Question 15

How do you view the commit history in Git?

Accepted Answer

You view commit history using the `git log` command. Options include `--oneline` for a compact view and `--graph` to visualize branch merges.
Code Example:
# Compact graph layout
git log --oneline --graph --all

Question 16

What is `git checkout` vs `git switch`?

Accepted Answer

Historically, `git checkout` was used for both switching branches and discarding file modifications. To clear ambiguity, Git 2.23 introduced two separate commands: `git switch` (dedicated entirely to switching or creating branches) and `git restore` (dedicated to reverting files).

Question 17

How do you rename a branch in Git?

Accepted Answer

You can rename the current branch using `git branch -m `. If you are renaming a different branch, use `git branch -m

`. Code Example: # Rename current branch locally git branch -m feature/new-login

Question 18

What is a detached HEAD state, and how do you resolve it?

Accepted Answer

A detached HEAD state occurs when Git checks out a specific commit hash rather than a named branch pointer. HEAD points directly to the commit. If you make commits here, they won't belong to any branch and will be lost on checkout. To save modifications, create a branch immediately from the detached HEAD using `git switch -c <new-branch-name>`.

Question 19

Explain the difference between origin and upstream in Git.

Accepted Answer

`origin` is the default name Git assigns to the remote repository you cloned from (your personal fork). `upstream` is the convention name given to the original parent repository that you forked from, allowing you to sync upstream changes back to your local repository.

Question 20

How can you undo a commit that was already pushed to a public remote branch?

Accepted Answer

If the commit is already public, do NOT use `git reset` as it rewrites history and breaks other developers' updates. Instead, use `git revert <commit-hash>` to create a new commit that undoes the changes. Stage, commit, and push the revert commit safely.
Code Example:
# Undoes the changes in that commit and pushes it safely
git revert d5c9a1
git push origin main

Git Version Control Interview

Difficulty Filters

Tools & Options

What is Git, and what is a Distributed Version Control System (DVCS)?

What are the three main states/areas in Git?

What is the difference between `git pull` and `git fetch`?

Explain the difference between `git merge` and `git rebase`.

What is a fast-forward merge?

What is `git stash`, and when is it used?

What is the difference between `git reset` and `git revert`?

Explain the differences between `git reset --soft`, `--mixed`, and `--hard`.

What is `git cherry-pick`?

What is `git reflog`?

What is a merge conflict, and how do you resolve it?

What is a Git commit hash (SHA-1)?

Explain Git hooks.

What is the purpose of the `.gitignore` file?

How do you view the commit history in Git?

What is `git checkout` vs `git switch`?

How do you rename a branch in Git?

What is a detached HEAD state, and how do you resolve it?

Explain the difference between origin and upstream in Git.

How can you undo a commit that was already pushed to a public remote branch?

Explore Related Tools

Publishing to Google Play

Machine Learning Tutorial

ASCII to Binary Converter

Binary to ASCII Converter

Binary to Octal Converter

Bulma Box Component – Simple Container with Shadow

Follow Us

Our Tools

Our Company

Special Tools