#AP Computer Science A: The Night Before 🚀

Hey there, future coder! Let's get you feeling confident and ready to ace this AP Computer Science A exam. This guide is designed to be your fast-track review, hitting all the key points you need to know. Let's do this!

#Why Programming? Why Java?

#Intro to Programming

Programming is the magic behind all the tech we use. It's essentially giving instructions to devices so they can respond to our actions. Think of it like this:

• Computers use 0s and 1s (binary) to operate.
• Low-level languages (like Assembly) talk directly to the hardware but are hard to read.
• High-level languages (like Java, Python, C++) are easier for humans to understand.

Courtesy of Android Authority

Courtesy of MalwareBytes

#What Is Java, How Does It Work, and Why Do We Use It?

Java is a super popular, high-level language. Here's why it's a big deal:

1. Simple: Easier syntax than languages like C.
2. Object-Oriented: Uses classes, objects, and methods.
3. Distributed: Connects easily with the internet and file systems.
4. Secure: Built to resist various attacks.
5. Architecture-Neutral: "Code once, run anywhere" thanks to the Java Virtual Machine (JVM).
6. Interpreted: JVM interprets bytecode for quick output.
7. High-Performance: Modern compilers are fast.
8. Multithreaded: Supports parallel programming.
9. Dynamic: Can add functionality with libraries.

#Getting Ready for Your First Program

You'll need an Integrated Development Environment (IDE) to write code. Here are a few popular options:

• Eclipse

  
  Courtesy of Red Hat Developer

• IntelliJ

  
  Courtesy of JetBrains

• Visual Studio Code

  
  Courtesy of Visual Studio Code

• BlueJ

  
  Courtesy of BlueJ

We'll use repl.it for examples, which is a great online IDE.

Courtesy of Repl.it

#The Anatomy of a Java Program

Let's break down a simple "Hello world!" program:'