2. Using Objects

In this unit, you will learn how to create and use objects in Java. The unit introduces a library that supports turtle graphics, which enables you to create 2D drawings and animations. This unit also introduces String and Math methods.

Unit 2 Table of Contents

• 2.1. Objects - Instances of Classes
  • 2.1.1. Intro to Objects with Turtles
  • 2.1.2. Programming Challenge : Turtle Drawing
  • 2.1.3. Summary
• 2.2. Creating and Initializing Objects: Constructors
  • 2.2.1. World Class Constructors
  • 2.2.2. The Turtle Class Constructors
  • 2.2.3. Object Variables and References
  • 2.2.4. Formal Parameters and Pass By Value
  • 2.2.5. Summary
• 2.3. Calling Object Methods Without Parameters
  • 2.3.1. Programming Challenge : Draw two letters
  • 2.3.2. Summary
• 2.4. Calling Methods With Parameters
  • 2.4.1. Programming Challenge : Turtle House
  • 2.4.2. Summary
• 2.5. Calling Methods that Return Values
  • 2.5.1. toString() Methods
  • 2.5.2. Methods with Arguments and Return Values
  • 2.5.3. Programming Challenge : Turtle Distances
  • 2.5.4. Summary
• 2.6. Strings
  • 2.6.1. String Operators - Concatenation
  • 2.6.2. Programming Challenge : Mad Libs
  • 2.6.3. Summary
• 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. Summary
• 2.8. Wrapper Classes - Integer and Double
  • 2.8.1. Programming Challenge : Debugging
  • 2.8.2. Summary
• 2.9. Using the Math Class
  • 2.9.1. Programming Challenge : Random Numbers
  • 2.9.2. Summary
• 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
• 2.11. Mixed Up Code Practice
• 2.12. Coding Practice
• 2.13. Multiple Choice Exercises
  • 2.13.1. Easier Multiple Choice Questions
  • 2.13.2. Medium Multiple Choice Questions
  • 2.13.3. Hard Multiple Choice Questions
• 2.14. Java Swing GUIs (optional)
• 2.15. Lesson Workspace

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