AP CSA Unit 3: Class Creation

Unit 3 of 4 · AP CSA 2025–2026 CED

Unit 3: Class Creation

Learn to design and build your own Java classes from scratch. This unit covers abstraction, constructors, accessors, mutators, static members, scope, and the this keyword — the foundation of object-oriented programming on the AP exam. Accounts for 10–18% of the AP exam.

9 of 9 lessons live — 100% complete

9Lessons
10–18%AP Exam Weight
108Practice MCQs
36Mastery MCQs
18Interactive Games

Coding Exercises

Write real Java in the browser and submit it. Every exercise is graded against hidden test cases, and your score reports to your teacher automatically. 9 of 9 are open so far; the rest unlock as they are built.

3.1Abstraction and Program DesignExercise 1 →🔒 Exercise 2
3.2Impact of Program DesignExercise 1 →🔒 Exercise 2
3.3Anatomy of a ClassExercise 1 →🔒 Exercise 2
3.4ConstructorsExercise 1 →🔒 Exercise 2
3.5Methods: How to Write ThemExercise 1 →🔒 Exercise 2
3.6Methods: Passing and Returning References of an ObjectExercise 1 →🔒 Exercise 2
3.7Class Variables and MethodsExercise 1 →🔒 Exercise 2
3.8Scope and AccessExercise 1 →🔒 Exercise 2
3.9this KeywordExercise 1 →🔒 Exercise 2
What You'll Master in Unit 3
  • Apply abstraction to identify the right attributes and behaviors for any class
  • Write constructors, accessors, and mutators following AP exam conventions
  • Explain pass-by-value for primitives vs. reference semantics for objects
  • Use static variables and methods correctly (and avoid the classic compile errors)
  • Resolve variable shadowing with this in constructors and methods
  • Predict output and spot bugs in class-design code
📖 Unit 3 Study Guide Complete reference & review 📝 Unit 3 Practice Exam Full timed MCQ test ⚙ Test Builder Custom quizzes from 586 questions 👩​🏫 1-on-1 Tutoring Live help from Tanner Crow
Lessons

All 9 Lessons — Start Anywhere

3.1 Abstraction and Program Design Conceptual › 3.2 Impact of Program Design Conceptual › 3.3 Anatomy of a Class Code Mechanics › 3.4 Constructors Code Mechanics › 3.5 Methods: How to Write Them Code Mechanics › 3.6 Methods: Passing and Returning References of an Object Code Mechanics › 3.7 Class Variables and Methods Code Mechanics › 3.8 Scope and Access Code Mechanics › 3.9 this Keyword Code Mechanics ›
Navigate the Course
Unit 1 Using Objects Unit 2 Selection & Iteration Unit 3 ✓ Class Creation Unit 4 Data Collections
← Unit 2 Unit 4 →

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