Unit 2: Using Objects

In this unit, you will learn how to create and use objects in Java.

Class Periods: 13-15

AP CSA Exam Weighting: 5-7.5%

Unit 2 Table of Contents

2.1. Objects - Instances of Classes
  • 2.1.1. What are Objects and Classes?
  • 2.1.2. Intro to Objects with Turtles
  • 2.1.3. Creating Turtle Objects
  • 2.1.4. Programming Challenge : Turtle Drawing
  • 2.1.5. Summary
  • 2.1.6. AP Practice
Start Section
2.2. Creating and Initializing Objects: Constructors
  • 2.2.1. Overloading Constructors
  • 2.2.2. The World Class Constructors
  • 2.2.3. The Turtle Class Constructors
  • 2.2.4. Object Variables and References
  • 2.2.5. Constructor Signatures
  • 2.2.6. Formal and Actual Parameters
  • 2.2.7. Programming Challenge: Custom Turtles
  • 2.2.8. Summary
  • 2.2.9. AP Practice
Start Section
2.3. Calling Methods Without Parameters
  • 2.3.1. Procedural Abstraction
  • 2.3.2. Programming Challenge : Draw a Letter
  • 2.3.3. Summary
  • 2.3.4. AP Practice
Start Section
2.4. Calling Methods With Parameters
  • 2.4.1. Tracing Methods
  • 2.4.2. Programming Challenge : Turtle House
  • 2.4.3. Summary
  • 2.4.4. AP Practice
Start Section
2.5. Methods that Return Values
  • 2.5.1. Accessors / Getters
  • 2.5.2. Methods with Arguments and a Return Value
  • 2.5.3. Programming Challenge : Turtle Distances
  • 2.5.4. Summary
  • 2.5.5. AP Practice
Start Section
2.6. Strings
  • 2.6.1. String Operators - Concatenation
  • 2.6.2. Programming Challenge : Mad Libs
  • 2.6.3. Summary
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2.7. String Methods
  • 2.7.1. String Methods: length, substring, indexOf
  • 2.7.2. CompareTo and Equals
  • 2.7.3. Common Mistakes with Strings
  • 2.7.4. Programming Challenge : Pig Latin
  • 2.7.5. Summary
  • 2.7.6. String Methods Game
Start Section
2.8. Wrapper Classes - Integer and Double
  • 2.8.1. Programming Challenge : Debugging
  • 2.8.2. Summary
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2.9. Using the Math Class
  • 2.9.1. Mathematical Functions
  • 2.9.2. Random Numbers
  • 2.9.3. Programming Challenge : Random Numbers
  • 2.9.4. Summary
Start Section
2.10. Unit 2 Summary
  • 2.10.1. Concept Summary
  • 2.10.2. Java Keyword Summary
  • 2.10.3. Vocabulary Practice
  • 2.10.4. Common Mistakes
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2.11. Mixed Up Code Practice
Start Practice
2.12. Toggle Mixed Up or Write Code Practice
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2.13. Coding Practice
Start Practice
2.14. Practice Test for Objects (2.1-2.5)
Take Practice Test
2.15. Multiple Choice Exercises
  • 2.15.1. Easier Multiple Choice Questions
  • 2.15.2. Medium Multiple Choice Questions
  • 2.15.3. Hard Multiple Choice Questions
Start Exercises
2.16. Unit 2 Free Response Question (FRQ) Practice
  • 2.16.1. FRQ Description of Level Class
  • 2.16.2. FRQ Practice
Start FRQ Practice
2.17. Java Swing GUIs (optional)
Explore Java Swing GUIs