Git and GitHub for Beginners - Crash Course

Key Takeaways

hi everyone welcome in this video we are going to learn about git and github why they are important and also how to use them so we're going to start off going over the terms and concepts that you will use in git and the ecosystem and then get into practical applications this tutorial will include everything from basic git repositories to what is github to some more intermediate concepts like branching and merging and forking and that kind of stuff i want to quickly introduce myself my name is gwen and i run a youtube channel called faraday academy where i upload coding tutorial videos and i also do a couple live streams a week mostly on python and javascript topics as well as some more general purpose coding videos you can also find me on twitter and instagram and pretty much everywhere by typing in gwen faraday and let's get started with the tutorial i want to start off here by defining what git is git is what we call a version control system that is free and open source and it's the most widely used version control system in development today most programmers interact with git on a daily basis so what is version control version control is basically a way that we as programmers track our code changes we basically save an initial version of our code into git and then when we update code we can save it into git again and again and again and again and throughout time as our code continues to change we can look back at all of the changes we have made over time this helps us to see and understand what we did when as well as track down bugs or go back to a previous version of the code if we need to so let's look at some of the terms that you're going to see in this video first of all i use the term directory which is also known as a folder on your computer when i reference the terminal or command line i basically mean an application that runs on your computer which is just an interface where you can type in text commands you can navigate around files and folders create files change update things install and run programs and much more you might also hear me use the term cli which is just the command line interface many programs that you install as a programmer will require you to interact with them via text commands in the command line so you will be typing out some text and hitting enter instead of say double clicking on a folder icon on your desktop just think of it as another way to run a program now you might be wondering why are we going to use the terminal or command line instead of using one of these beautiful applications that handle interacting with git for us well as programmers it's always good to use the terminal so you learn the get commands and workflow of git as well as become accustomed to it as a developer you are going to be using the terminal a lot to install clis run programs search for things etc throughout your development career and learning git is a great way to get started with the command line cd stands for change directory it's basically the same thing as when you double click on a folder using the icons on your desktop while in the command line if you want to move into a folder or even up to a parent folder you'll use cd followed by the directions to get to whatever folder on your system you want to get to a code editor of course is a place to write code you'll probably see this in a lot of different programming videos but just in case you are unfamiliar with it you can write code anywhere in a text document word processor anything but there are special ones that are designed with lots of tools and features for programmers and these are called code editors now some people get confused by the word repository because it has multiple meanings but in the world of programming it usually refers to a git repository which is basically just your project or the folder place where your project is kept you can call it a repository people also sometimes confuse git and github now git is the tool that tracks the changes in your code over time github is a website where you host all of your git repositories being online it makes it easy to work in groups with other people and organize your projects into a portfolio for you to show potential employers so here are some of the get commands we're going to cover in this video which you will be typing into your terminal or command line on your computer they are clone for example if there's a repository that is not on your local machine but it's on github and you want to bring it down on your local machine so you can use it locally you use the clone command by the way all of these commands are lowercase not uppercase as we're going to see as we go through the examples in this video when you have updated files or created or deleted files and folders you're going to want to tell get that you made changes and that you would like get to track those changes so you use the add command for that as i said earlier git is there for you to save the changes you make in your code so you do that through a commit and we call it committing your changes once you have made changes locally on your computer and you are ready to put them in git you tell git to track them through the add command you save your files to get through the commit command and then you upload your files to a place like github or another what we call remote repository or github alternative like bitbucket gitlab and there's many of them you do this through the push command when there are changes to your code on github and you want to bring those to your local machine then you use the pull command you pull down changes from the remote repository those are all the commands that i want to cover to get started again we're going to go over examples of each of these the first thing you will need to do is of course sign up for an account on github this is pretty straightforward you enter minimal information and then you sign up for an account you will get an email that will ask you to verify and then you can log into your account when you log in you will either be on this page which is your profile page that you can access from this drop down menu or you might be on the dashboard page here either way you will have access to this green button here or this plus sign and the drop down here where you can create a new repository now a repository is basically a project it's all of your coding files and folders for whatever kind of application that you are building for example this is a repository that i have it's for a curriculum app that i've been building you can see the mock-ups pretty straightforward application and in this repository this is my complete project with the folders and all of my coding files are inside of these folders for this one application each application or project is in a separate repository so i'm going to go ahead and create a new repository here give it a name demo repo by the way repo is just short for repository i'm going to leave these settings as they are and click create repository now you can create your files and folders for this repository locally on your machine or you can create them straight in the online editor on the github website so i'm going to go ahead and create a basic markdown file called a readme and this is the most basic file that you will find in almost every project that contains text to describe what the project is about what it does and any other relevant information so i'm going to click here create a new file i'm going to name it read me dot md for markdown markdown is basically an easy way to format your text in these sort of files so i'm going to come down here and type some text now markdown has all these shortcuts like one hashtag for a main header so i'm just going to put demo here and then some plain text so i'll put some description and then i'll scroll to the bottom to commit the file in other words save this file i just want to point out really quickly that this create readme.md is placeholder text but if you don't write anything else here when i commit this it will use this text as the default so let me commit and you can see here that this is the commit message from when i saved this readme file and now you can see the readme file which because it's named readme.md is the default file that github always shows down here i can also go into the file here which is the same thing except with a few different options here and in either screen i have this edit this file option so i'm going to go ahead and do that i'm going to simply change this to an exclamation point now the default text instead of create readme.md is now update readme.md which isn't that descriptive but it's okay for right now so i'm going to commit and by committing i saved my changes here and if i go to the demo repo it shows my last commit message here as update readme.md now if i want to see my entire history of changes in other words every commit that i've made i can come here to commits and each commit has a unique identifier and i can also see the message or the title that i wrote on these commits so i can come back to this one and see what was added this green with the plus signs means these lines were added to this file and then i'll go back and in the updated commit it shows me this red with the minus sign that means this line was deleted and then the green with the plus means this line was added anything that's white means it stayed the same so this is a very basic view of seeing changes now what about using this on your local machine if you are using a mac or linux operating system you should already have git installed you can check this by opening your terminal or command line application and typing in get space dash dash version if git is not already installed i highly recommend checking out this tutorial by atlassian which i will link in the description below it walks you through how to install git on any operating system now i do want to note for the windows installation when you download the get windows installer i recommend you choose the get bash option from the install menu you can of course use command prompt and it will set up get in command prompt for you but in the past i've had an easier time with git bash on windows for mac it gives you a few different options for install but i highly recommend you use the homebrew package manager if you can and it takes you through all of the steps here but again you probably already have get installed if you're using a mac or linux and don't need to worry about this there's just one more piece of setup before we continue with the rest of the git tutorial and that is getting a code editor of course you can write code in whatever you want any type of word processing software will do from notepad to microsoft word but there are specific ones made for coding and many of them are really good and free visual studio code is a free code editor made by microsoft is widely used with people learning to code and professionals alike so you can install it for free from code.visualstudio.com it's available on every major operating system mac windows and linux now i have visual studio code open with no files or folders inside if you haven't used this before then all of these icons on the side are how you're going to navigate around your project and use your tools so i'm going to come to this top one and this bar comes out where i'm going to see all my files and folders i'm just going to open a folder real quick in this test folder i'm going to go to my git then this is an empty folder that i have i'm going to click open and now i have a folder that's open in visual studio code that i can actually add files and folders to but i'm not going to right now because i'm actually going to pull the repo that we created at the beginning of this tutorial here on github i'm going to pull that to my local system using git so in visual studio code i have access to a terminal from here that i'm going to use if i come up to the top in the view menu i'm going to come to terminal and select it and now it opens this terminal here by the way the only reason why this says git is because my folder is named git and because i've opened the folder here it automatically uses that as the directory for my terminal so now i want to clone down my repo to my local machine i want to pull all that code down here so i can work with it locally i'm going to use a command called git clone and then in clone or download here clone with ssh exactly what we just set up so i'm going to copy this go back to my terminal and paste and i'll hit enter and now we can see a folder here which is my repo from github that's pulled down into the directory that i am in so i'm going to move inside this folder real quick from the command line which i can just do by cd and then the name of the folder to change directory into the folder so now i am inside of the folder demo repo which was the name of the repository we created on github so when it pulled it down it gave the folder this name so my whole repository is inside of that folder and now it says git master now this might look different on your machine this part looks different on every machine i have a specific setup to make it look like this but either way you will probably see some kind of indication that you are in a git repository now now how do you know this looks like a regular folder and a regular readme file well there's actually a hidden folder that you can't see here and that you won't see on most operating systems unless you have selected to show hidden folders and that is called the dot get directory so there's just a special command in my terminal that i will use to show you that folder now the la command that i used here is actually a mac shorthand for ls space dash la which means list everything in the directory including hidden files and folders so if you're not on a mac i don't think la will work for you but you can use ls space dash la to do the same thing so you can see here's the readme file and then there's something dot git and because it's blue here that means it's actually a folder and this hidden git folder actually stores all of the files that save your commits or your code changes over time it has all of the changes recorded in the history of this repository which includes the ones we made on github.com so now let's make some more locally i'm going to go into the readme file and come here and add a subheader not too creative i'm just going to call it subheader and then some more text now that i have changed this file i need to save the changes in git so i do that through a commit still so first i'm going to use the get status command now the git status command shows me all of the files that were updated or created or deleted but haven't been saved in a commit yet so for example if i come here and i create a new file i'm going to call this index.html and i'm just going to put a quick div inside with nothing else and now let me rerun the get status command and now you can see i have one file that's been modified and one file that it says is untracked meaning git doesn't know about this file yet so you have to tell git to track the file before you can save it to git to do that you need to use the get add command and then tell it which files to track now most of the time or a lot of the time you see people use a period which means you're telling git to track all of the files that are listed here in both the untracked and the modified section so both the changes we made to readme and the new file index.html would be staged with git if we did git add period because it includes all of the files you could also optionally tell it just the names of each individual file or folder that you want get to track in this case i'm just going to use the dot now i'm going to use git status again and now you can see that all of the changes have been tracked that's why they show up differently now and they are ready to be committed so i'm going to come here and do git commit dash m now dash m is for message and you need to have a message in order to commit your files the message could be one character in meaningless if you want but there needs to be a message and ideally that message should have something to do with the what and why behind the commit you're making so i'm going to add a message here added index.html and this is just the title of the message if you remember from the web interface there were two boxes a title and a description this first dash m and what's inside of the quotes is a message you can add a second one for the description box so i can say sum description and i'll click enter and now it gives me some information two files change five insertions but we've still only saved our code locally the commit isn't live on github yet we make it live by using another git command called git push which means i want to push this live to a remote repository where my project is hosted in order to push them to github under your account you're going to have to prove to github that you are the owner of your account so you have to connect your local machine to your github account somehow the way this is done is by using ssh keys you need to start by generating a key locally using the ssh keygen command then you specify the type of encryption and then the strength of encryption and at the end you need to include your github email address this is just a test for me because i already have keys set up so i'm just going to put a fake email address but make sure that the email address you enter here is the same one you use to log into your github account click enter now the default file for the ssh key is inside your user directory in the dot ssh directory and it will be called id underscore rsa i'm going to give it a different name here because i already have a key under that name you can optionally enter a passphrase for your key here or leave it blank so i'm just going to click enter to leave it blank and my key has been generated now i am going to search for the key that i just generated and now i find that there are two so there's testkey and testkey.pub so pub testkey.pub the key that you are going to upload to your github interface pub stands for public it's called your public key which means that it's okay for other people to see this key the key that was generated without the dot pub extension is called your private key and is the one that you have to keep secure on your local machine you don't share this key with anybody how it works is that the public key you put on github and then every time you want to connect to github or push your code on github or use your account via your local machine you use your private key to show github that you are the one that generated this public key it's a mathematical proof that only this private key could have generated this public key i'm going to print out this public key and your key should look something like this ssh rsa starts with this it has a bunch of characters in the middle and it ends with your email now you need to copy this whole key which you can do by highlighting it in your terminal or command line which automatically copies it you don't need to do control or command c because control c actually means something completely different in the terminal not copy there's also a terminal command that allows you to copy it's called pb copy and then you do the less than symbol and then the path to your file so it's in our user home directory and i didn't actually push it put it in the dot ssh directory but this is the directory you would have your key in and then it's just test key dot pub and now it's copied to my clipboard on github i'm going to go to settings and in the list of all settings i'm going to go to ssh and gpg keys and you can see any ssh keys associated with your account then you just click on new ssh key you can give it whatever title you want this is just for your reference and then you paste your key in here and i'm going to remove the extra enter at the end and now add ssh key to confirm my password and now you can see my key was successfully added the only thing left to do is to make sure that your local get command line interface knows about the key you just generated and i'm going to link all of these steps in the description below you need to start the ssh agent then if you're using version 10.12.2 or later you will need to modify this file your ssh config and add this text to it i'm going to just show you how to get into that file now paste the location of the file in your ssh directory and then anywhere in this file perhaps at the end you can paste in that information i'm not going to do that because i already have my file set up so i'm going to delete it after you do that you'll run this ssh add command from your terminal and then your key will be set up to work with git again all of the information that i covered with keys here is going to be linked in the description below but this is the general way that you will do it with any operating system although there might be some slight variations now there are two more arguments we have to put here the first one is origin and the second one is master now origin is an option set for us here and is basically a word that stands for the location of our git repository master is the branch that we want to push to and we'll get into what that means in a minute i'm going to click enter and now i'll refresh this page and you can see my code changes are all live on github now you can also see that there are three commits two that we made online on github.com and one that we made locally and pushed up to github.com of course this was our commit message that we made locally and this was the description that we wrote after that second dash m we can see all of our file changes that we made locally here as well so this was to demonstrate how to create a new git repository using github but what about if you start a repo locally so let me exit out of these and i will create a new folder here called demo repo 2. drag it outside so now it's in a completely separate folder from the other git repository that we have but this one's not a git repository yet and nothing's in there so i'm going to move into that folder in the terminal demo 2. so now i'm in demo 2. you can see it's not a git repository even if i look for that hidden get folder it's not there so let me first add a file in here and i'm again going to add a readme file dot md and i'm going to add a header demo 2 and some text now if i want to turn this into a git repository i can use the command line and say git init and it says initialize git repository in yada yada this folder and now you can see i have the get keyword there and if i do get status i can see there's this untracked readme file i will go ahead and add that file either with the period or the name of the file git status again okay so the file is ready to be committed and now i will do git commit dash m created readme and now i'll put description here and enter now what if i want to push this live let's try get push origin master and now you can see it's giving me this error fatal origin does not appear to be a git repository because we didn't clone this down from a git repository we didn't already create this repo on github we created it locally so git is saying i have no idea where to push this to because it's not connected to anything so we have to create that connection and first the easiest way to do this is by creating an empty git repository up on github so i'm going to come here create new repository i'm going to call this demo repo 2 don't need a description going to leave all this here now i have another empty repository so to start pushing here i'm going to copy this and say git remote now remote means somewhere else but not on this computer we're going to use this to add a reference to the remote repository on github and then i'm going to say add origin and paste that link that i copied and i can check that by saying git remote dash v and it shows any remote repositories that i've connected to this repo now that these are set up i can now use get push origin master just as i did before now there's a shortcut here because if i don't want to type out this whole thing every time in the future i can just use git push but i have to set something called an upstream meaning this is where i want to push it to by default so i'm going to do dash u for set up stream and then enter and in the future i can just use git push without typing out origin master it says to github looks like everything was pushed just fine i will refresh this page and i can see the readme that i just added so that's how you initialize a repository locally and push it to a remote location like github so let's review the workflows that we've gone over so far and compare the flow of adding code in the github interface versus writing it locally so when we first started working in the github interface we wrote some code in the readme and then we committed our changes we saved them to get now notice there wasn't an ad step here we never did a get add to stage changes well that's because github handles that for us so really by committing in github we are adding and committing at the same time and then that was it really because it was our repository we had full access to change whatever we wanted we could just update the code just by committing it in the github interface of course we didn't have to push the code because it was already live on github there's no other remote repository because it's already in the remote repository now if we didn't own the repository or we didn't have access rights or we needed other people to review our code before we merged it in with all the rest of the code then we would also have to take the extra step of making a pull request which is something we're going to cover later in this video so let's compare this workflow if we're just writing code on github versus doing it locally and then pushing it up to github so locally in our text editor we wrote the code and then we had to do git add to let get know about the changes and then we saved them to git using the git commit command and then we pushed them to the remote repository on github using the get push command and that updated github's code or the code in the github repository with our changes that were made locally and then just like before if we didn't have access rights or we needed a code review before we merged changes in we'll need to make a pull request so these two methods cover the most basic ways to use git by using the github web interface and then doing it locally if you have any questions about this then please leave them in the comments below otherwise let's move on to git branching let's first go over some of the concepts of branching and then we'll dive into a practical example now what is git branching you've seen in our examples that we're on something called the master branch now master is a naming convention for the main or the default branch in a repository so if you're just working off of one branch that's where your code will live and all your code all your commits everything will be in that one branch now this is called branching because it starts to look more like a tree when you have multiple branches so we saw earlier that we had a master branch we were committing to that master branch but we could also make another branch we'll call it feature branch so let's talk about what happens when we create a new branch at first the code on master and this new feature branch will be exactly the same but as you make updates to the feature branch those changes are only seen in the feature branch so if you make changes on the feature branch you make a commit to save those changes onto that branch and then you switch back to the master branch you won't be able to see any of the changes that you made on that feature branch each individual branch has no way of knowing what commits or what changes have been made to any other branch each branch is only keeping track of what changes are made on its own branch now you can continue to change the code on master branch and save it through a commit to the master branch and then if you switch back to the feature branch likewise you will not be able to see the changes that you just saved to master why is this useful it's extremely useful because you will be building out new features to applications that may break your code or they are not finished yet and you don't want to save them to the main master branch you want to work on them in kind of a sandbox area so you can write all the code you need and get it correct and in the state that you want before you merge it back into the main branch of the code base and this is really helpful when you have many different people working in the same repository or a lot of different branches going on at once one very common thing that you'll see in development is that you'll be working on let's say this feature branch for a week or more and you have all of these changes that you've made and then you find out there's this major bug that you have to fix real quick so for that we make this other branch called it a hotfix branch here represented by yellow and you can see that i made the change in one commit to fix whatever bug was wrong with the code on its own branch i made sure it was working correctly and then i merged it back into the master branch now that we've gone over the concepts of branching let's dive into the command line and try it out and now i'm using a full screen terminal just so i have more space as i'm running different get commands that are going to take up more screen space to show you but it works the exact same way as the terminal inside of vs code so i'm back in my terminal inside of my demo repo again and you can see here i have information about my git branch again you might see this presented in different ways it shows you're on the master branch if i type in git branch you can see that i currently only have one branch and it's master and you can also see there's a star beside it and that means that i am currently on that branch so i'm going to hit the letter q here to get out of that and now i'm going to create a new branch so i do that with git checkout and git checkout is what you will use to switch between branches but to tell it to create a new branch use dash b and then you give it the name of your branch so in this case i'm going to call it feature now if you're working in a real application with people you want to make this name as descriptive as possible some people like to use feature slash the ticket number or description or you can use hyphen and then you could give it the issue number like if it's a github issue number 11 or whatever convention you want to use and then you can make this longer if you want and put some more details i'm going to call this feature readme instructions because i'm just going to be updating a section of the readme click enter and now it says i switched to a new branch meaning i created this new branch called feature readme instructions and now you see that my branch changed so now if i do get branch again i have two branches listed here and the top one is starred and highlighted so it shows me which branch i'm currently on i'm going to hit q and like i mentioned git checkout will switch between branches so now that i am on this feature readme instructions i can check out master and now you see i switched to master i'll do git branch shows i'm on master now and i will do another get checkout feature readme instructions you see that i hit the tab button and it auto filled the rest of the branch so i didn't have to type out the whole long name you can also hit tab even if you don't start at the beginning like in this case i started typing feature and then hit tab but i could actually start typing instructions and hit tab and it still auto-completes now this is very useful because eventually when you work in a repo you're going to start a lot of stuff with feature or with bug or hotfix or whatever so only your last few words will be unique so that's just something useful to know so now i'm back on the feature readme instructions branch and i'm going to make some changes on this branch so i'm in my code here i'm going to come into my readme and make a new section i'm going to say just local development or something and then give it one step i wasn't going to say open index.html in your browser just as a demo all right i saved that and you can see in vs code it gives me this m here meaning it's been modified since i've last checked this into git that's kind of a nice feature to have to see which files you've added and which files you've modified right in your text editor all right now that i've modified some files here i'm going to do the get status command again and it says i modified readme so first i'm going to save things that i've changed on this branch so i'm going to do the git add command and i'm just going to stage the readme changes and now i will do a git commit dash m and say oops i have to put that in quotes so updated readme okay so you can see i have one file changed for insertions so now it's saved to git but it's only saved on this feature readme instructions branch so if i do a git checkout master come back to my code and you can see the changes aren't here because they're only on that other branch now if i want to here i can go ahead and merge these two branches locally using the get merge command but before i do that i just want to double check and see the code that i'm merging in which i can do through the get diff command now diff or diffing shows me what changes have been made it compares two versions of the code and shows me all of the lines that have been changed and you kind of saw this in the get interface because you saw a nice visual representation of the diff where it showed in green with a plus sign the lines that had been added and then in red with the minus sign the lines that had been removed and let me say get diff and the name of the branch hit enter and now you can see it shows which file it's talking about this readme.md file and in white it shows text that was already been there that hasn't been changed and then it shows that my master branch doesn't have some of the changes that are in my other branch so i'm going to hit q here to get out of this all right now i could go ahead and like i said use the git merge command pass in the branch and it'll merge in those changes but the more common pattern that you're going to see is pushing these changes on that branch up to github and then making a pr so i'm going to change back to the feature branch and now i'll do git status and it says i have no changes to commit because they've already been committed but i do need to push them up to github so let me run git push and now you can see since i'm on a new branch it says that i need to tell it which branch on github i want to push to now the answer is almost always that the branch will be named the same thing on github and on your local machine so i could copy this line and now you'll notice this set upstream flag here is the same thing that we were doing before with the dash u it's just shorthand for set upstream so i'm going to hit enter here and now it's pushed up to github and it's even giving me a hint for how to create a pull request on github by giving me these instructions here so what is a pull request or a pr it's basically a request to have your code pulled into another branch in the example we're using today we have a feature branch and we want to have our code pulled into the master branch so we make a pr from the feature branch to the master branch now once we have made a pr anyone can review our code comment on it ask us to make changes or updates now after you make a pr you can also update the code just by making additional commits and pushing them up to github as long as it's on the same branch that you're making the pr with once the pr is merged you'll generally delete your feature or source branch and to switch back to the master branch then when you want to make additional coding changes you will create another new branch and start the process over make your commits make a pr and then merge again and i could go straight to this url but i'm going to show you how to do it manually on github first so i look at my github interface and you can see already github picked up on the fact that i just pushed a new branch so now it's asking me right here if i want to compare this new branch to another branch and create a pull request and it takes me to this screen here now sometimes this is confusing for people which branch is being merged into which branch this github interface does a pretty good job because of the arrow so you can see that the branch you're comparing this feature readme instructions will be merged into the base so there's always a base branch where all the code is going to get merged into and then there's the branch you're comparing so now i have this message i have a title that says i updated readme and i can put some more description here so usually i'm going to put a list of the changes that i've made and maybe some description as to why i made certain decisions so here i'm just going to say added section about local development to the readme and i will create a pull request now that i've created a pull request i can actually come here in the interface i can see any comments that people have made on the pull request or i can write more comments of my own i can look through all the commits i've made that i'm trying to merge into master right now and i can also look at all the files that have been changed and see the diff of what's been added removed or updated another thing i can do right here is if i want to make a comment about a particular line of code that i've written i can press the plus button this blue plus button and now i can make a comment there i'm just going to say add a new subheader and add it as a single comment and you can see that the comment appears at the line of code where you hit the plus button this is a really nice way if there are multiple people working on a repository to make comments about specific lines of code and then usually the person who created this pr will reply to them with an explanation or make another commit if changes need to be made to the code or something all right so i'm going to go ahead and merge this pr and you'll notice that i added the single comment it says resolve now because i'm the owner here i have full permissions i don't have to resolve i can still merge the pr if you don't have permissions or your repo set up in a certain way then you might have to resolve comments before you can merge anyway i'm just going to merge here confirm and merge successful now that the pr is merged i'm going to go over to the code and if i scroll down you can see that i am on the master branch and my changes are also here so the branch was successfully merged so locally now i'm going to switch to the master branch and if you look at the code the changes aren't there yet and that's because they are only on github and i need to pull them down to my local environment so to get the changes on my local master branch from origin i'm going to do git pull now if i didn't already set the upstream i would have to do git pull origin master but i already have an upstream set here so i'm just going to do git pull and then enter and you can see one file changed for insertions and now if i look at my code i can see my local master has also been updated with the changes from the branch and now that i am done with that feature branch i'm going to do get branch and it's still there even though i'm not going to be using it again because you don't really reuse branches that you've already merged into your master branch so i'm going to go ahead and delete this branch so i'm going to do get branch dash d and then the name of the branch and again i can tab over so i'll hit enter and now it says i deleted that branch so now if i do get branch and i only have master again all right well that's all fine and great and works well but in real life you're not always going to have such an easy time merging there's something called merge conflicts in git where basically you're building your own code writing a bunch of code on your own branch maybe other people are writing code on their branches and master is getting updated from multiple different places so it's possible for multiple people to change the same files and so sometimes git doesn't know which code you want to keep or which code is redundant or which code you want to get rid of so you'll have to manually do that let's try that out let me create another branch i'm going to do git checkout dash b and then i'm just going to call this quick test all right i'm on the quick test branch now i'm going to come into index.html and i'm going to add a p tag here and say world and p all right so i modified this file let me go ahead and do git status it's always a good idea to do git status before you commit anything looks good what i can also do from here is do a git diff enter and it shows me all of the changes that i've made since my last commit so i'm gonna hit q and now i will commit these now generally the workflow has been git add and then file name or a period to add everything in this directory this time there's a shortcut because we've just modified one file and the file has already been committed to get in the past which is why it says modified and not created so what i'm going to do is get commit and then instead of dash m i'm going to do dash a which stands for add and m at the same time for message then i'm going to put my commit message so this basically adds and commits at the same time but it only works for modified files not for newly created files because if it's newly created you have to stage that with git and let get know about it first for my message i'll just say added world okay and now i have one file changed to insertions now let me go to my master branch git checkout master you can see i don't have the changes from my other branch there but what if i updated the same line so on master now i'm updating line two and here i'm going to put there so hello there so now master has a line 2 but the new branch i created also has a line 2. now everything is fine now because both branches are separate but what if i try to merge these two together who's line two is going to be put there so let's try that i'm going to go to my quick test branch so i'm going to do git check out quick test and now it's actually giving me an error and not letting me change branches because i have local changes that line two that i added in master it says it's going to be overwritten if i change branches so it's asking me to commit before i change so that way that line two will be saved to get in the master branch and won't be lost when i change branches now stashing is a little bit beyond the scope of this tutorial but it's basically a way for you to stash your changes somewhere and then you can retrieve them later but it's not making a commit to get it's like a temporary holding place so we're not going to do that i'm just going to go ahead and commit so let me do git status first all right and i'm going to use the shorthand because i only have the modified file there so i'm going to do git commit am and then a commit message i'm going to say added there and now i should be able to check out press the up arrow key i should be able to check out this quick test branch and before i merge master into this branch i'm going to diff against master real quick and it shows me the changes here so now i'm going to do merge so remember how i said before that merging locally wasn't the regular pattern well it isn't for merging branches into master but master gets updated as you go along as you're working on your project because maybe other people are merging into master and you don't have those changes in your branch but you don't want to get too far behind master as you're working because then it's going to be really difficult to merge later so as changes are made to master in the github repo you're going to want to pull those down to your local master branch and then whatever feature branch you're working off of like quick test here you'll want to use git merge master to keep your branch up to date with what's going on in master so that's what we're doing here get merge master hit enter and now it says we have a conflict so we have a merge conflict in index.html so there are a couple ways to fix merge conflicts interfaces like github give you an interface to fix them you can also fix it in the terminal but the easiest way to fix merge conflicts is directly in your code a nice code editor like vs code will let you click buttons like accept the current change or accept incoming or take both of these but you can also come in here make the changes that you want and delete these lines that get added this lets get know that there's a conflict and first between this head and these equal signs it shows the code that we have on the current branch that we are on and then it shows the code coming from the other branch that we're trying to merge in so in this case i am just going to delete these lines and save both of the changes but in this case one to line two and one to line three and this is just letting git know what we want to do because it didn't know how to handle the conflict now we have handled it and deleted the conflict markers we can now look here and see that we need to make another commit even though it seems like we are adding and subtracting the same things we basically need to make a commit because we have fixed the merge conflicts so i'm going to say here get commit dash am and i can say merged in master or updated with master or something like that and now i've officially updated my branch with the changes that have been happening on master branch and i can continue coding whatever feature or bug fix or whatever i'm doing on this quick test branch so what if we make a mistake what if we accidentally add something or commit something to get and we didn't mean to do it we can actually undo our stages or are commits so let me come to readme i'm going to add another line here and say have fun okay so i've made a change here on line 12 and back in my demo rebuild i'm going to do git status so now let's say i want to get add this readme and let me do git status again and you can see before it said change is not staged and now changes to be committed meaning they've been staged already but what if i want to undo staging what if i didn't mean to stage this file i can actually easily undo it by using the get reset command so i can either do git reset with no arguments or i can say git reset and just the name of the file that i want to unstage so here i'm just going to do the plain git reset and it gives me a list of the files so unstate changes after reset readme now if i do another get status it shows me that this file is no longer staged so what if i want to undo a commit so let me go ahead and add the readme file and then i'm gonna come and commit readme and i'm gonna say added install step now if i do get status you'll see there's nothing to commit because all changes have now been committed well if i made a mistake on that commit i can use that same get reset command and this time i'm going to say git reset head in all caps and what head means to get is a pointer to the last commit so i'm telling it to do something with the last commit and then i'm going to say tilde 1 which is telling git instead of pointing to this last commit that i just made right here i want you to go back one commit further and head will now point back one commit further meaning it will completely undo the commit that i just made let me click enter and now you can see it says i unstaged the changes so i'm going to say git status and what happened was that it unstaged and uncommitted those last changes so if i do git diff you'll see that git picks this up as a new change now now if you have many different commits you might want to go back to a specific commit or undo multiple commits and for that there's no quick pointer in git like the uppercase head pointer where you can just look at the last commit or use that to undo the last commit but you can see a log of all your commits and you'll see that these are arranged in reverse chronological order so this is the latest commit that we made and you can see with the commit message that's also why it's important to write a good commit message because it's easier for humans to scroll through and see which commit is which to get these commits are differentiated with this unique hash here so if you want to go back to a certain commit you can copy one of these hashes let's say i want to go back to added world before i added the their line so i want to basically undo when i merged this there from master into this branch so let me copy this commit hash and by the way when you see all of these commits you can scroll down with spacebar and now it shows this is the end so i'll say quit so i'm going to do git reset and then the hash of that commit and it's unstaged any changes made to these files after this commit so you can see the changes are still there i added have fun and this line three in the index.html but they are just not saved in get or staged with git any longer so what if i was just testing something out and i want to get rid of all of the changes after a certain point while i can do that by using the get reset command as well let me just grab a commit hash so i'm going to go back just a couple random commits to this commit right here where i said updated readme i'm gonna hit q [Music] and now i'm gonna do git reset dash dash hard meaning i want all of the changes to not just be unstaged but to be completely removed so head is now pointing to a different commit because i've undone several commits now and if i look in my files we've just completely gone back in time and erased the latest updates so those are the basics of branching merging fixing merge conflicts and undoing staging and commits that you've made one more thing that i want to quickly mention is forking you may have seen this already in the git interface you can hit fork here and then it's going to make a complete copy of the repository now why would you want to fork well you probably don't want to fork your own repo because you already have full access to all of the code here but you don't for other people's repos so let me find just a random repo on github okay so here's vue.js so let me click on this and i actually don't have access to change anything in this repo so if i want to make a pr against this repo and request for my changes to be added or if i just want to be able to branch off of the code in this repo and do whatever i want with it then i want to fork it so i'm going to hit the fork button here and fork it to my user account these are just groups that i'm a part of on github sometimes it takes a minute to fork over all the code especially with vue.js because it's a large repository all right and now you can see the repo is no longer under the view js organization now it's under my personal github and now that i've forked this i have complete control to make any updates or changes that i want to this code so if i want to come into readme and hit the pencil update this i can say hide there and now i can come to the bottom and commit changes again so i can say updated readme or whatever i want i'm just going to leave it with the default text again commit to the dev branch so before we worked off the master branch as being the default branch but sometimes when you're working in a larger project with other people you're going to want to create multiple branches like master staging and dev for different kinds of environments so in this case dev is set to the default branch for this repository instead of master so i'm just going to commit my changes directly to dev and you can see my changes here of course they aren't part of the main vue.js view repository but they're part of the one that i forked because i forked a complete copy of that repository including the branches associated with it and you can see dev is marked as the default so now what if i wanted to get my changes back into this vue.js repository of course i don't but what if i did i would go and create a pull request so new pull request and then as my base the place that i want to merge my changes into i would put the repository that i forked from this vjs repository and the branch and i want to compare that with my repository that i forked and the branch on my repository that i updated of course i'm not going to click create pull request because this is just a demo i can also see the diff down here of the changes that i've made and what commits i've made to this branch on my fork now if i want to merge within my fork i can do that easily let's say of course there isn't anything to compare because i'm comparing the same branch here but i could merge into any other branch let me find master here so i could merge straight into master and you can see i can create pull requests now i created a pull request and i'm going to create pull request and you can see they had a bunch of default text added to the pull request information but i'm just going to go ahead and merge go back to the code if i scroll down of course i'm on dev it says hi there and now if i go to master it also has my changes on master because i merged them generally speaking after we merge a branch into one of our default branches like master then we would clean up the branch that has just been merged in other words we would delete it from github and from our local machine because we're not using that branch anymore but it's a little bit different when we use branches like dev staging and master because generally you're merging your feature branches into either dev or master and you have dev and master and sometimes staging reserved for just merging into so you don't make any changes on dev and master themselves you'll just be merging other branches into dev or master depending on how your code base is set up in a large project like vue.js we would merge all of our feature branches or bug fixes or whatever into the dev branch and then delete the branch that we just merged in and then when all the changes on the dev branch are ready those get merged into master but dev never gets deleted just like master never gets deleted those kind of stay around forever all the other branches are just temporary so me having my own fork allows me full reign full access full control of crud operations create read update delete whatever i want to do with all of this code all of these files and if i want to make some major updates what i'm going to do is fork the repository which i already did pull my fork down to my local machine make all the updates that i want to test them out whatever i want to do i'll push them back up to my fork and then i will create a pr against the original repository thanks so much for watching i hope that you enjoyed this video and that you also got something out of it if you did then don't forget to like the video and subscribe to the free code camp channel don't forget to check out my youtube channel called faraday academy where i do weekly videos and live streams on python and javascript and other related programming topics i would also appreciate if you would leave me a comment here and let me know what you liked about the video or any other feedback that you might have have a great day and i hope you enjoy using git