Working with Arrays and Collections →easyMultiple SelectObjective-mapped

1Z0-829 Working with Arrays and Collections Practice Question

Which TWO statements are true about ArrayList in Java 17? (Choose two.)

⚠ Common exam trap

Many candidates confuse ArrayList's lack of synchronization with thread safety, or mistakenly think it implements Set or Queue due to its membership in the Collections Framework, but ArrayList is strictly a List implementation.

Answer choices

Why each option matters

Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.

Correct answer & explanation

✓

It implements the List interface

ArrayList implements the List interface, which is a core part of the Java Collections Framework. This allows ArrayList to be used polymorphically wherever a List is expected, providing ordered, index-based access to elements.

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

✓
It implements the List interface
Why this is correct
ArrayList implements List.
✗
It implements the Set interface
Why it's wrong here
It does not implement Set.
✗
It implements the Queue interface
Why it's wrong here
It does not implement Queue.
✓
It extends AbstractList
Why this is correct
ArrayList extends AbstractList.
✗
It is synchronized
Why it's wrong here
It is not synchronized; use Collections.synchronizedList.

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1Z0-829 Working with Arrays and Collections Practice Question

Why each option matters

Option-by-option breakdown

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