Consider: List list = Arrays.asList("A", "B", "C"); list.add("D"); What is the result?

An ArrayIndexOutOfBoundsException is thrown

Working with Arrays and Collections →mediumMultiple ChoiceObjective-mapped

1Z0-829 Working with Arrays and Collections Practice Question

Consider: List<String> list = Arrays.asList("A", "B", "C"); list.add("D"); What is the result?

⚠ Common exam trap

Many candidates confuse `Arrays.asList()` with `new ArrayList<>(Arrays.asList(...))`, assuming the returned list is a regular mutable `ArrayList`, but the exam tests the fixed-size behavior of the wrapper list.

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

✓

An UnsupportedOperationException is thrown

The `Arrays.asList()` method returns a fixed-size list backed by the specified array. This list does not support structural modification operations like `add()` or `remove()`. Calling `add()` on such a list throws an `UnsupportedOperationException` at runtime.

Answer analysis

Option-by-option breakdown

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

✗
An ArrayIndexOutOfBoundsException is thrown
Why it's wrong here
Exception type is UnsupportedOperationException.
✗
The list becomes [A, B, C, D]
Why it's wrong here
Cannot add element to fixed-size list.
✗
A ClassCastException is thrown
Why it's wrong here
No casting issue.
✓
An UnsupportedOperationException is thrown
Why this is correct
Arrays.asList returns fixed-size list.

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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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