nzingaholloman/lab-1-nholloman

Lab-1

Debugging and GitHub

This is the first lab for COMP 167 Computer Program Design at North Carolina A&T State University

Instructor: Dr. Kelvin Bryant - [email protected]

The objective of this lab is to introduce you to git and GitHub, two tools that will be used extensively this semester, as well as the NetBeans IDE.

What is Git?

Git is a system that allows developers to store multiple versions of a single project, called branches. It also allows developers to keep their local copy of code up to date with remote copies. This has many advantages, mainly that it provides backup copies of code, and makes it easy to collaborate with other developers in the same office, or across the world.

Git stores projects in special directories called repositories. A repository is nothing more than a directory, or folder, that has its changes tracked by git. Therefore, most small projects (and every project in this class) should be contained in a single git repository, or folder. You may not know this yet, but you've already created your first git repository! It is called "Lab-1-YOUR-USERNAME" and you're looking at the remote copy of this repository right now. This remote copy is hosted on GitHub.

What is GitHub?

GitHub is a service that hosts remote repositories for millions of developers around the world. Companies like Apple, Google, Microsoft, RedHat, Adobe, Twitter, PayPal, and Facebook use GitHub to host their code. GitHub is also the world's largest host of open source projects, making it a treasure trove for young developers to learn from millions of projects.

In this class, we will complete all programming assignments on GitHub, this will allow TA's to easily check your work, and will protect your work from loss should anything happen to your computer.

Setiing Up for the Lab

Now that you know some of the basic terms, lets move into this lab. The first thing you must do is clone the repository, or create a local copy of the repository on your computer. to do this, you will need to launch the git bash app on your lab computer. If you are using your own computer, install git by following the instructions for your operating system on the git website.

1. Clone the repository.
   • After opening git bash, create a directory to hold all of your git repositories. Type the command mkdir COMP167 and press enter. Now, if you type the command ls and press enter you should see your new COMP167 directory listed. Change to this directory by entering cd COMP167 and pressing enter.
   • You will need to acquire the link to your remote git repository. Click the green Clone or Download button above these instructions and copy the link provided.
   • Finally, you can clone your repository by entering git clone [PASTE-LINK-HERE]. Note that the square brackets are only to separate your information from the actual command you should type. After pasing your link, you command should look something like this git clone https://github.com/NCAT-COMP167-Spring2018-Lab-1-ccannon94.git.
2. Open the repository and project.
   • You must now navigate to your repository in git bash. First, run the ls command to view the contents of your current directory. You should only see one subdirectory, this is the repository you have just cloned. To navigate to your repository, run cd [REPOSITORY-NAME-HERE].
   • Now that your repository is open in git bash, it's time to open NetBeans, the IDE we will use in COMP167.

What is an IDE?

An IDE, or an Integrated Development Environment, is a tool developers use when writing software. Good IDE's endeavor to make often repeated tasks as easy as possible for developers, as well as help developers avoid errors by providing services like autocompletion, linting, and debugging. NetBeans, the IDE we will use, was created by Oracle specifically to work for Java developers, like us.

Opening the Project

For this lab, the NetBeans project is already created for you. In future labs, you will learn how to create and configure your own NetBeans project.

1. Launch the NetBeans application.
2. Select "File" and "Open Project". Navigate to your newly cloned repository and double-click on the project called Contacts.
3. The left-hand side of your screen should show your project hierarchy, source files, or files ending in the .java file extension, are located under "Contacts -> Source Packages -> contacts".
   • All source files in a NetBeans project will need to be located in a package. Source files not in a named package are said to be in the default package.
4. Open all source files and take a look at the project you have been provided.

Debug the Program

The project is currently in an unworkable state. Use the error messages and the debugger provided by NetBeans to try and restore your program to a working state. TA's will not point out errors or instruct you on how to fix them for the first part of class. Use online resources and your problem solving skills to the best of your ability, and collaborate with other students in the lab. When you think you have a fully functioning program, ask a TA to check it.

Commit and Push!

These final steps are the most important parts of this lab. Committing and pushing often is absolutely essential to using git effectively. Every time you make a change, and that change works successfully, you should commit and push your work. This has two major benefits. 1) Committing and pushing backs up your data against any hardware failure of your local machine. 2) You can roll back to your last commit easily in git by using the command git reset --hard. Therefore, every time you succeed at something, you should commit, so that if your next change fails, you don't need to waste time undoing every single wrong thing you typed (trust me, there will be a lot in this class).

To commit and push, follow these steps:

1. Save ALL files changed in NetBeans.
2. Return to your git bash window, and run the command git add .. In this case, the period represents your current working directory, and this command tells git to add all of your changes inside the current directory (your git repository) to the staging area, which means they are ready to commit.
3. Run the command git commit -m "[COMMIT-MESSAGE-HERE]". This will make a commit with a commit message of your choosing.
   • Commit messages should be no more than 55 characters, and should explain the change that this commit will make to your code. For example "Adds drag and drop functionality to ListView" or "Refactors while loop to include a base case" are excellent, concise, clear commit messages.
4. Finally, run git push to push your local changes to your remote repository, which as we discussed, is hosted on GitHub.
   • At this point, you should refresh your GitHub page to see that your code has pushed successfully.