- A
An ArrayIndexOutOfBoundsException is thrown.
Index 1 is out of bounds for length 1.
- B
The first element is swapped with itself.
Why wrong: No swap occurs due to exception.
- C
A new array with length 2 is returned.
Why wrong: Method returns void.
- D
The array remains unchanged.
Why wrong: An exception occurs before any change.
Question 58 of 509
1Z0-811 Arrays and Methods Practice Question
This 1Z0-811 practice question tests your understanding of arrays and methods. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Given the method: 'public static void swapFirstTwo(int[] arr) { int temp = arr[0]; arr[0] = arr[1]; arr[1] = temp; }'. What is the effect of calling this method with an array of length 1?
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 ArrayIndexOutOfBoundsException is thrown.
The method accesses arr[0] and arr[1] without verifying the array length. When called with an array of length 1, index 1 is out of bounds because valid indices are 0 only. Java performs runtime bounds checking, so an ArrayIndexOutOfBoundsException is thrown.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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 this is correct
Index 1 is out of bounds for length 1.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
The first element is swapped with itself.
Why it's wrong here
No swap occurs due to exception.
- ✗
A new array with length 2 is returned.
Why it's wrong here
Method returns void.
- ✗
The array remains unchanged.
Why it's wrong here
An exception occurs before any change.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Oracle often tests the misconception that a method with a void return type will silently do nothing or leave the array unchanged, when in fact an unchecked array access throws an exception.
Detailed technical explanation
How to think about this question
In Java, array bounds are checked at runtime by the JVM; accessing an invalid index throws ArrayIndexOutOfBoundsException, a subclass of RuntimeException. This is a common pitfall when writing utility methods that assume a minimum array length, and it highlights the importance of defensive programming with length checks (e.g., if (arr.length < 2) return;).
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the 1Z0-811 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
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FAQ
Questions learners often ask
What does this 1Z0-811 question test?
Arrays and Methods — This question tests Arrays and Methods — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: An ArrayIndexOutOfBoundsException is thrown. — The method accesses arr[0] and arr[1] without verifying the array length. When called with an array of length 1, index 1 is out of bounds because valid indices are 0 only. Java performs runtime bounds checking, so an ArrayIndexOutOfBoundsException is thrown.
What should I do if I get this 1Z0-811 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 30, 2026
This 1Z0-811 practice question is part of Courseiva's free Oracle certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 1Z0-811 exam.
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