Sat Mar 08 - Written by: Samridha
Git QnA
Explore Git fundamentals, commands, version control concepts, and common Git interview questions for developers and testers.
Git Overview
What is Git?
Git is a distributed version control system that helps developers track and manage changes in their source code efficiently. It is widely used for collaboration in software projects.
Why Use Git?
- Allows multiple developers to work simultaneously on a project.
- Tracks changes and reverts to previous versions if needed.
- Supports branching for feature development without affecting the main codebase.
- Enables easy collaboration using remote repositories like GitHub, GitLab, or Bitbucket.
Key Git Concepts
- Repository (Repo): A folder containing a project’s code and its version history.
- Commit: A saved snapshot of code changes.
- Branch: A separate line of development for features or fixes.
- Merge: Combines changes from one branch into another.
- Rebase: Moves commits from one branch to another to maintain a linear history.
- Staging Area: Where changes are prepared before committing.
- Remote Repository: A Git repo hosted on a cloud service.
- Local Repository: A Git repo stored on your local system.
Setting Up Git
Configure Git
git config --global user.name "Samridha"
git config --global user.email "m@m.com"
# Git Commands Cheat Sheet
## Create a Repository
```bash
git init # Initializes a new Git repository in the current directory
Clone a Repository
git clone <repo-url> # Clones a repository from a remote source
Check Status of Changes
git status # Shows the status of staged, unstaged, and untracked files
View Commit History
git log # Displays commit history
Push Changes to Remote Repository
git push origin <branch_name> # Pushes local changes to a remote branch
Pull Latest Changes from Remote Repository
git pull origin <branch_name> # Fetches and merges updates from the remote branch
Working with Branches
Create and Switch to a New Branch
git branch <branch-name> # Creates a new branch
git checkout <branch-name> # Switches to the specified branch
Merge Branches
git checkout main # Switch to the main branch
git merge <branch-name> # Merges the specified branch into the main branch
Undoing Changes in a Branch
Revert a Commit
git revert <commit-id> # Creates a new commit that reverts the specified commit
Reset a Commit (DANGEROUS)
git reset --hard <commit-id> # Resets branch history to the specified commit
Saving and Restoring Uncommitted Work
Stash Changes
git stash # Temporarily saves changes that are not ready for commit
Apply Stashed Changes
git stash pop # Restores the most recent stashed changes
Rebase vs. Merge
Merge
- Combines changes from another branch and creates a new commit.
Rebase
- Moves the commits from one branch on top of another, making the history linear.
git checkout main # Switch to main branch
git rebase feature-branch # Apply feature branch commits on top of main branch
Git Overview
What is Git?
Git is a version control system used for tracking changes in source code. It helps developers collaborate efficiently and manage code history.
Why Use Git?
- Tracks and manages changes to code.
- Facilitates team collaboration in software development.
- Supports branching for feature development.
- Allows reverting to previous code versions if needed.
Common Git Terminology
- git add - Adds the latest changes to staging before committing.
- git commit - Stores a snapshot of the staged changes.
- git push - Pushes local commits to the remote repository.
- git branch - Creates a parallel version of the repository.
- git clone - Creates a local copy of a remote repository.
- repo (repository) - A project folder managed by Git.
- git merge - Combines changes from one branch into another.
- conflict - Occurs when two branches modify the same line of code.
- git rebase - Moves commits from one branch to another to maintain a linear history.
- remote repository - A Git repository hosted on a cloud service (e.g., GitHub).
- local repository - A Git repository stored on your local system.
- HEAD - A pointer to the latest commit in the current branch.
Setting Up Git
Configure Git
git config --global user.name "samridha"
git config --global user.email "m@m.com"
Initialize a Repository
git init # Initializes a new Git repository in the current directory
Clone a Repository
git clone <repo-url>
Check Status of Changes
git status
View Commit History
git log
Push Changes to Remote Repository
git push origin <branch_name>
Pull Latest Changes from Remote Repository
git pull origin <branch_name>
Working with Branches
Create and Switch Branches
git branch <branch-name> # Creates a new branch
git checkout <branch-name> # Switches to the specified branch
Merge Branches
git checkout main # Switch to the main branch
git merge <branch-name> # Merges the specified branch into the main branch
Undoing Changes in a Branch
Revert a Commit
git revert <commit-id> # Creates a new commit that reverts the specified commit
Reset a Commit (DANGEROUS)
git reset --hard <commit-id> # Resets branch history to the specified commit
Saving and Restoring Uncommitted Work
Stash Changes
git stash # Temporarily saves changes that are not ready for commit
Apply Stashed Changes
git stash pop # Restores the most recent stashed changes
Rebase vs. Merge
Merge
- Combines changes from another branch and creates a new commit.
Rebase
- Moves the commits from one branch on top of another, making the history linear.
git checkout main # Switch to main branch
git rebase feature-branch # Apply feature branch commits on top of main branch
Git Interview Q&A
1. What is the difference between git fetch and git pull?
| Command | Description |
|---|---|
git fetch | Downloads changes from the remote repository but does not merge them. |
git pull | Fetches and automatically merges the changes into your local branch. |
Example:
git fetch origin
git diff main origin/main # Compare local and remote versions
git merge # Manually merge changes
2. What is commit squashing?
- Squashing combines multiple commits into a single commit to keep history clean.
git rebase -i HEAD~4 # Squash the last 4 commits
3. What does a force push do?
- A force push (
git push origin main --force) overwrites the remote branch with your local branch.
4. How do you rename a branch?
git branch -m <old-name> <new-name>
5. What is Git Cherry Pick?
- Cherry-picking allows applying a specific commit from one branch to another without merging the entire branch.
git cherry-pick <commit-id>
6. How would you find a specific commit?
git log --grep "commit message"
7. How to start an interactive rebase?
git rebase -i HEAD~4 # Rebase the last 4 commits interactively
8. How do you reset the last commit?
| Scenario | Command |
|---|---|
| Before pushing | git reset --soft HEAD~1 (Keeps changes unstaged) |
| After pushing | git revert HEAD (Creates a new commit to undo the last commit) |
9. How does git revert work?
git revertcreates a new commit that undoes the last commit without modifying history.
10. Difference between Git and SVN?
| Aspect | Git | SVN |
|---|---|---|
| Architecture | Distributed Version Control System (DVCS) | Centralized Version Control System (CVCS) |
| Offline Work | Can commit changes offline | Requires network access |
| Branching | Lightweight and fast | Heavyweight and slow |
| Merging | Easier and supports rebase | Complex and less flexible |
Summary
- Git is a powerful distributed version control system.
- It supports branching, merging, and collaboration across teams.
- Commands like
git add,git commit,git push, andgit pullare essential for daily workflows. - Understanding rebase, cherry-picking, and interactive rebasing helps in managing cleaner histories.
- Git interview questions often focus on version control concepts and best practices.