Git is a distributed version control system that enables developers to track changes in their code over time. Unlike centralized version control systems, Git gives each developer a complete copy of the repository, making operations like branching and merging faster and more flexible. This guide covers fundamental Git concepts, commands, and workflows to help you effectively manage your code.
Git and GitHub are tools we will be using throughout the course to track and store changes to our code and allow you to collaborate with others and keep everything in sync.
Note: You do not need GitHub to use Git, but you cannot use GitHub without using Git.
🎥 Video: Git & GitHub Crash Course For Beginners (32 mins) - A comprehensive introduction to Git and GitHub
Version control is a system that records changes to files over time, allowing you to recall specific versions later. It gives developers the ability to:
Git is currently the most widely used version control system in software development due to its speed, distributed nature, and robust branching capabilities.
🎥 Video Short: What exactly is Git?! (1 min)
Git addresses several critical needs in modern software development:
Below is an example of checking your Git history. This shows 2 most recent commits. One added a user authentication feature and the other fixed a navigation menu bug on mobile devices. We cover more about history/branching in the Git Branches guide.
$ git log
commit a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6q7r8s9t0
Author: John Doe <john.doe@example.com>
Date: Mon Sep 11 14:23:44 2023 -0700
Add user authentication feature
commit b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6q7r8s9t0u1
Author: Jane Smith <jane.smith@example.com>
Date: Sun Sep 10 11:05:32 2023 -0700
Fix navigation menu bug on mobile devices💡 Tip: Git is valuable even for solo projects. It provides a safety net for experimental changes and allows you to document your development journey.
🎥 Video: Why Use Git? (6 mins) - The benefits of version control for teams and individuals
GitHub is a code hosting platform for version control and collaboration. While Git is the version control system that runs locally on your computer, GitHub is a remote service that hosts your Git repositories online.
⚠️ Note: While GitHub is the most popular Git hosting service, alternatives include GitLab, Bitbucket, and Azure DevOps.
🎥 Video: Git vs. GitHub: What's the difference? (10 mins) - Understanding the relationship between Git and GitHub
A repository is a collection of files and the history of changes made to those files. It contains the entire project and its version history.
# Create a new repository
$ git init my-project
Initialized empty Git repository in /path/to/my-project/.git/
# Clone an existing repository
$ git clone https://github.com/username/repository.git
Cloning into 'repository'...
remote: Enumerating objects: 125, done.
remote: Counting objects: 100% (125/125), done.
remote: Compressing objects: 100% (80/80), done.
remote: Total 125 (delta 58), reused 95 (delta 40)
Receiving objects: 100% (125/125), 2.02 MiB | 3.45 MiB/s, done.
Resolving deltas: 100% (58/58), done.A commit is a snapshot of your repository at a specific point in time. Each commit has:
# Stage changes for commit
$ git add file.txt
# Create a commit with a message
$ git commit -m "Add user authentication feature"
[main a1b2c3d] Add user authentication feature
1 file changed, 25 insertions(+), 2 deletions(-)
# View commit history
$ git log --oneline
a1b2c3d Add user authentication feature
b2c3d4e Fix navigation menu bug on mobile devices
c3d4e5f Initial commitBest practices for commits:
🎥 Video: How to commit better with Git (12 mins) - How to write effective commit messages
A branch is a parallel version of the repository that allows you to work on different features or fixes without affecting the main codebase.
# Create a new branch
$ git branch feature/login
# Switch to a branch
$ git checkout feature/login
Switched to branch 'feature/login'
# Create and switch to a new branch (shorthand)
$ git checkout -b feature/payment
Switched to a new branch 'feature/payment'
# List all branches (* indicates current branch)
$ git branch
main
feature/login
* feature/paymentCommon branching strategies:
This is a diagram of Gitflow.
🎥 Video: Git Branches Tutorial (33 mins) - How to work with branches effectively
A fork is a copy of someone else's repository that lives in your GitHub account. Forking allows you to freely experiment with changes without affecting the original project. To create a fork, click the Fork button on the top right of a repository's page on GitHub.
# After forking on GitHub, clone your fork locally
$ git clone https://github.com/your-username/forked-repository.git
# Add the original repository as a remote called "upstream"
$ git remote add upstream https://github.com/original-owner/original-repository.git
# Verify remotes
$ git remote -v
origin https://github.com/your-username/forked-repository.git (fetch)
origin https://github.com/your-username/forked-repository.git (push)
upstream https://github.com/original-owner/original-repository.git (fetch)
upstream https://github.com/original-owner/original-repository.git (push)💡 definitions for above output:
remote repository: The repository that you forked from. upstream: The original repository that you forked from. (not technically "yours") origin: Your forked repository.
To get started, you will need to download, install and configure Git on your computer and create a free GitHub account here.
git version to verify Git was installed.Git uses a username and email to associate commits with an identity. Let's define your user with the following commands
git config --global user.name "Your Name"
git config --global user.email "email@example.com"When you connect to a Github repository from Git, you will need to authenticate using either HTTPs or SSH. We recommend connecting over HTTPS and caching your GitHub credentials in Git following these instructions
The general development flow is:
💡 Tip: Commit often and commit early, this way you'll never have that gut sinking feeling of overwriting or losing changes.
Below are some walkthroughs steps for:
Local Git repositories are created and managed locally on your computer.
To begin, open up a terminal and create a new directory, open it and perform git init to create a new repository
mkdir newproject
cd newproject/
git initNow that your local Git repository is up and running, you can update it with any changes you make.
Check for any changes that have been made or new files since your last commit
git statusStage any files with changes (or new ones) you would like to commit
git add <path>: This stages an individual file or directorygit add .: This stages all files with changesCheck to see what was added git status
Commit the changes to your local repository with a brief message outlining the changes
git commit -m "your message about the commit"Note: Git will notice any new files inside the repository but it won't track the files unless you explicitly tell it to.
To put your project up on GitHub, you will need to create a repository for it. To create a new repository:
For more details, checkout GitHub documentation on Creating a new repository.
Since we've already created our repository locally, we want to push that onto our newly created GitHub repository.
Connect your local repository to GitHub repository
git remote add origin https://github.com/yourUserName/yourRepoName.gitPush your local changes to your remote repository
git push -u origin mainBrowse to your GitHub repository web page to refresh and see your code
To update your local repository to the most recent changes that you or others have push to GitHub, execute git pull
Note:
git pulldoes two things behind the scene: fetch & merge remote changes. Git tries to auto-merge, but unfortunately this is not alway possible and may result in conflicts. You are responsible to merge those conflicts manually by editing the files shown by Git.
If you are collaborating on a project, or just want access to your project from a different computer, you can clone the project from the GitHub repository.
Cloning a repository is typically only done once, at the beginning of your interaction with the project. Once you have cloned a repository, you won't need to clone it again to do regular development.
To clone a repository:
Type git clone, an the paste the repository URL & press Enter
git clone https://github.com/YOUR-USERNAME/YOUR-REPOSITORYThroughout the program, you may be provided initial code to get you started. If so, follow this steps to setup your own repository:
.zip fileOnce you have the starter code in your computer, let's open up a terminal to initialize the git repository.
cd /path/to/unzipped/project
git init
git add .
git commit -m "initial starter code setup"
