AP CSA Unit 3 Full Review | NEW 2026 |

In this video, I go over Unit 3 of AP Computer Science A (Objects, Classes, and Methods) in a simple, beginner-friendly way. This unit focuses on how Java programs are built using classes and objects, and it introduces the core ideas behind object-oriented programming (OOP), which is heavily tested on the AP exam and FRQs. 💻 I used the CodeHS IDE to demonstrate Java examples, object creation, and method calls, along with step-by-step tracing to show how objects store data and interact with methods. 📚 Topics covered: Classes vs Objects Instance variables (fields) and how objects store data Constructors and how objects are created using new Methods (void vs return methods) Parameters vs arguments Encapsulation (private variables + getters/setters) Access modifiers (public vs private) Static vs instance methods The this keyword Method overloading (if included in your class) Object references and aliasing toString() method and printing objects Scope of variables (local vs instance) Method calls and dot notation Basic object tracing and FRQ-style questions ⚠️ Note: This unit is all about thinking in terms of objects, not just lines of code. A lot of AP questions will test whether you understand how data is stored inside objects and how methods interact with that data step-by-step. Tracing code carefully is the key to mastering this unit.