GitHub

Read the Git and GitHub documentation provided in the Tools section.

Git Commands: When to Use Them

`git clone`

When to use:
Use this the first time you want to copy a remote repository (e.g., from GitHub) to your computer.

Command:

git clone <repository_ssh_url>

Tip: Run this only once per project. After that, use git pull to update your local copy.

`git pull`

When to use: Use this to bring in the latest changes from the remote repository to your local repository.

Command:

git pull

Tip: Always run this before starting new work to make sure your files are up to date.

`git add`

When to use: Use this to stage (mark) new or modified files that you want to include in the next commit.

Command: For one file git add <file_name> For all changes git add .

`git commit`

When to use: Use this after git add to save a snapshot of your staged changes in the local repository.

Command:

git commit -am "Describe the change you made"

Tip: Write clear and meaningful commit messages so you and others understand the change.

`git push`

When to use: To send your committed changes from your computer to the remote repository (e.g., GitHub).

Command:

git push

Typical Workflow

git pull: get the latest updates.
Edit your code/files.
git add: if new files have been added or to stage your changes.
git commit -am "message": save your changes locally.
git push: upload your changes to GitHub.

HW 07 - Scanner

DUE DATE: September 16, 2025

Go inside the folder homework, and create a subfolder 09_15_snooze. Inside this folder, you will write the following java file:

NoonSnooze.java: This program should ask the user for a number that represents the number of minutes, snooze, that have elapsed since 12:00 pm (noon) and prints the resulting time. Assume a 12-hour clock (with 'am' and 'pm'). You must not use loops. If the snooze value is negative, print a warning message: "No negative values are allowed".

Examples:

If the user input is 50, the output should be 12:50 pm

If the user input is 100, the output should be 1:40 pm

If the user input is 721, the output should be 12:01 am

If the user input is 11111, the output should be 5:11 am

If the user input is -10, the output should be No negative values are allowed

HW 06 - Practice Variables and Expressions

DUE DATE: September 15, 2025

Go inside the folder homework, and create a folder 09_12_practice. Inside this folder, you will write the following programs:

Write a Java program (Fractions.java). In this program you will initialize 4 integers that represent each part of two fractions, namely the numerator and denominator of the first fraction and the numerator and denominator of the second fraction. Your program should add the two fractions and print out the result.

For example, a sample program run might look like this:

  The numerator of the first fraction is 1
  The denominator of the first fraction is 2
  The numerator of the second fraction is 2
  The denominator of the second fraction is 5
  The sum of 1/2 + 2/5 = 9/10

Write a Java program (WorkShift.java). A doctor works 20 hours, 42 minutes, and 16 seconds in one shift at a hospital. Convert the total shift time into seconds and display that information.

NOTE: You must use at least ONE compound operator (+=, -=, *=, /=, %=) to complete this program.

Quiz Reminder

The Summer Assignment Quiz will be on Tuesday, September 16th

HW 05 - Data Types and Variables

DUE DATE: September 11, 2025

Data Types and Variables

Directions: Create a new folder named 09_10_variables inside your homework directory in your assignments repository: .../APCSA1/apcsa-assignments-fall-YourUsername/homework/09_10_variables

Inside this folder, write the following programs:

Write a Java program (Temperature.java) to convert temperature from Fahrenheit to Celsius degrees. You must use variables.

Output:

50.0 degrees Fahrenheit is equal to 10.0 Celsius

Write a Java program (Calculator.java) that calculates the sum of two numbers (int or double). You must use variables.

Output:

10 + 12 = 22

Create a file TrickyCalc.java and copy the following code inside. Run the program. Create a file answers.txt or answers.md and respond to the following questions:

What do you notice about the mySum value?
What is the value of checkResult, and why do we get that result?

public class TrickyCalc{
   public static void main(String[] args){
       double mySum = 0.1 + 0.1 + 0.1;
       double tmp = 0.3;
       boolean checkResult = mySum == tmp;

       System.out.println("0.1 + 0.1 + 0.1 = " + mySum);
       System.out.println(mySum + " == " + tmp + " is " + checkResult);
   }
}

Don’t forget to add your new files to Git, then commit and push your changes. After that, go to GitHub and verify that your files are there. I will not accept any excuses tomorrow if your homework is missing.
Double check that your files are organized like this in your repo:

apcsa-assignments-YourUsername
  classwork
    09_09_hello_world
      HelloWorld.java
  homework
    09_09_welcome
      Welcome.java
    09_10_variables
      Temperature.java
      Calculator.java
      TrickyCalc.java
      answers.txt or answers.md

HW 04 - Git commands practice

DUE DATE: September 10, 2025

The objective of this homework is to create a java file, add it, commit and push to a remote repository.

In your local machine at home, go to the folder where your assignments repo was cloned ...../APCSA1/apcsa-assignments-fall-YourUsername/, execute git pull and create a folder homework.
Create a folder 09_09_welcome inside the homework folder.
Write a java file Welcome.java (this should be the path ...../APCSA1/apcsa-assignments-fall-YourUsername/homework/09_09_welcome/Welcome.java). In this program, you should introduce yourself. Print two lines to the console using the System.out.println() method.

In the first line, state your name, and in the second line state your favorite hobby.

Your output should be in the following form:

My name is ...
My favorite hobby is ...

Run git status. What does it show?
To add the new file to the repository, run the following command from the root (top-level, ...../APCSA1/apcsa-assignments-fall-YourUsername/) of your repo, not from inside the homework folder:

git add homework/09_09_welcome/Welcome.java
Run git status again. What does it show this time?
Commit and push the file to your repo.
Go to GitHub, Welcome.java should be there.
Tomorrow, we will pull the changes using the lab machines.

HW 03 - Git

DUE DATE: September 9, 2024

Set up SSH
Configure your home computer to connect to GitHub using SSH, if you have not done that already.
Accept the Assignments Repository
- If you haven’t already, accept the assignments repository using this link.
- After accepting, a repository will be created under your GitHub account.
- If you run into any issues, contact me.
Clone the Assignments Repository
- Open your GitHub assignments repository for this class.
- Click the green Code button, select SSH, and copy the link provided (it will look like git@...).
- Create a folder named APCSA1 anywhere on your computer.
- Open your terminal, navigate inside the APCSA1 folder, and run:
  git clone PASTE_THE_LINK_YOU_COPIED_FROM_GITHUB

Quiz Reminder

The Summer Assignment Quiz will be on Tuesday, September 16th.

HW 02 - Summer Assignment, Piazza, Git

DUE DATE: September 8, 2025

Summer Assignment

Follow the next steps to share your CodingBat Summer work with me.

Log in to your CodingBat account.
Click on prefs
Teacher Share section: type the teacher's email jnovillo@stuy.edu
Click on Share
Update the Memo section: type YourPeriod_YourLastName_YourFirstName (no spaces) like this 1_smith_peter
Click on Update Memo

Submit the complete Java program that was assigned (Google Classroom).

Piazza

Post a question or comment about the summer assignment. Feel free to reply to peer's comment/question to generate a productive discussion.

GitHub

Set up Git and SSH keys on your home computer and practice using Git commands. If you have any questions, post them on Piazza, and I encourage everyone to help your peers by answering those questions.

HW 01 - Forms

DUE DATE: September 5, 2025

Complete the following forms:

CW 04 - Scanner

DUE DATE: September 15, 2024

Save your file here: .../APCSA1/apcsa-assignments-fall-YourUsername/classwork/09_15_scanner/NightOut.java

Follow these directions to write your NightOut.java program:

You and a friend are going out for the night. You have decided to treat your friend, so you’re paying for the whole night. However, since you have a fixed amount of money to spend on fun things, you need to track how much the outing will cost so you can update your budget.

Write a program to help yourself estimate what the total cost of the night will be. Your program will estimate the cost by taking the cost of the activities for one person and estimating how much it will cost for two people.

Here’s what you know about your activities:

Dinner - you know you typically get cheap dinners, so you expect that your friend’s dinner will be twice as expensive as yours

Laser Tag - since laser tag is charged per person, you and your friend will cost the same

Ice cream - you like the triple scoop, but your friend likes a single scoop. Your friend’s ice cream will cost 1/3 as much as yours.

Your program should ask how much YOUR dinner cost, how much laser tag costs per person, and how much YOUR ice cream costs. It should then compute how much your friend’s costs will be based on the information above. Be sure your program takes the input in this exact order. Then print how much dinner will cost (for both of you), how much laser tag will cost (for both of you), and how much the ice cream will cost (for both of you). Then print the grand total for the evening.

Your output should look something like this:

How much does dinner usually cost? 

12.63

How much is laser tag for one person? 

17.50

How much does a triple scoop cost? 

27.00

Dinner: $37.89

Laser Tag: $35.0  

Ice cream: $36.0

Grand Total: $108.89

CW 03 - Casting

DUE DATE: September 12, 2025

Create a java file Casting.java and implement a method that:

Receives 2 integers
Divides the two ints
Prints the result

The trick here is that we want the division of the two ints to result in a double! Casting values to doubles will be necessary to solve this exercise. Here is an example:

x = 3

y = 4

Output => 0.75

Save your file here: .../APCSA1/apcsa-assignments-YourUsername/classwork/09_12_casting/Casting.java

CW 02 - Expressions

DUE DATE: September 12, 2025

Indicate the value and type of each of the following expressions. If the expression does not compile or causes a runtime exception, put an X.

You do not have to submit this work, but do it on your notebook so you can review it at any time.

Expressions

2 + 5

8 / 10 * 1.5

12 % 7

2 + 3 * 4

2 + 3.0 * 4

1 / 1 / 0

1.0 / 1 / 0

“Happy” + “Face”

“8+2” + “5”

“10” + 8 + 12

2 + 4 + "5" + 6
 
27 % 4

CW 01 - Hello World and Git

DUE DATE: September 9, 2024

The objective of this exercise is to create a java file, add it, commit and push to a remote repository.

In your local machine, go to the folder where your assignments repo was cloned ...../APCSA1/apcsa-assignments-fall-YourUsername/, execute git pull and create a folder classwork.
Create a folder 09_09_hello_world inside the classwork folder.
Write a java file HelloWorld.java that prints the message "Hello World!".
Run git status. What does it show?
To add the new file to the repository, run the following command from the root (top-level, ...../APCSA1/apcsa-assignments-fall-YourUsername/) of your repo, not from inside the classwork folder:

git add classwork/09_09_hello_world/HelloWorld.java
Run git status again. What does it show this time?
Commit and push the file to your repo.
Go to GitHub, HelloWorld.java should be there.

Welcome to APCSA

Lesson 06 - User Input

Lesson 05 - Casting

Lesson 04 - Expressions and Assignment Statements

Lesson 03 - Data Types and Varialbes

Lesson 02 - Intro to Java

Lesson 01 - Git

GitHub

Git Commands: When to Use Them

`git clone`

`git pull`

`git add`

`git commit`

`git push`

Typical Workflow

HW 07 - Scanner

HW 06 - Practice Variables and Expressions

Quiz Reminder

HW 05 - Data Types and Variables

Data Types and Variables

HW 04 - Git commands practice

HW 03 - Git

Quiz Reminder

HW 02 - Summer Assignment, Piazza, Git

Summer Assignment

Piazza

GitHub

HW 01 - Forms

CW 04 - Scanner

CW 03 - Casting

CW 02 - Expressions

CW 01 - Hello World and Git