AP CSA Unit 4 Day 26: Arraylist Loop Adding

Unit 4, Data Collections • Cycle 2
Day 26 Advanced Practice • Harder Difficulty
Focus: ArrayList Loop Adding Hard ArrayList Loop Adding

Advanced Practice Question

Format: ArrayList Loop Adding

What is the final size of the ArrayList?
ArrayList list = new ArrayList<>();
list.add(1);
list.add(2);
list.add(3);

for (int i = 0; i < 3; i++) {
    list.add(list.get(i) * 2);
}

System.out.println(list.size());
Difficulty: Hard  |  Topic: ArrayList Loop Adding  |  Cycle: 2 (Advanced)
Why This Answer?

Initial size is 3. Loop runs exactly 3 times (i = 0, 1, 2) based on the condition i < 3. Each iteration adds one element. Final size: 3 + 3 = 6.

Common Mistake
Watch Out!

Thinking the loop will run based on list.size() which changes during the loop (it doesn't - loop condition is i < 3).

AP Exam Strategy

Loop condition i < 3 is evaluated once at the start of each iteration. It doesn't dynamically change with list.size().

Master This Topic

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

  • Understanding arraylist loop adding
  • Tracing code execution accurately
  • Avoiding common pitfalls
View Unit 4 Study Guide

Ready for More Challenges?

Cycle 2 questions prepare you for the hardest AP CSA exam questions.

Study Games Practice FRQs
Back to blog

Leave a comment

Please note, comments need to be approved before they are published.