Unit 4 Cycle 2 Day 6: ArrayList Wrapper Types

Unit 4, Data Collections • Cycle 2
Day 6 Advanced Practice • Harder Difficulty
Focus: ArrayList Wrapper Types Hard ArrayList Wrapper Types

Advanced Practice Question

Format: ArrayList Wrapper Types

What happens when you compile this code?
ArrayList nums = new ArrayList();
Difficulty: Hard  |  Topic: ArrayList Wrapper Types  |  Cycle: 2 (Advanced)
Why This Answer?

ArrayLists require wrapper classes (Integer, Double, Boolean), not primitives (int, double, boolean). Must use ArrayList.

Common Mistake
Watch Out!

Forgetting that ArrayList can't use primitive types.

AP Exam Strategy

ArrayLists need wrapper classes: Integer not int, Double not double, Boolean not boolean.

Master This Topic

This Cycle 2 HARD question tests arraylist wrapper types. Review Unit 4 concepts to build mastery of data collections.

  • Understanding arraylist wrapper types
  • Tracing code execution accurately
  • Avoiding common pitfalls
View Unit 4 Study Guide

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