The answer is 5. This is correct because Java passes object references by value, meaning the method `modifyArray` receives a copy of the reference to the original array; when the method executes `arr = new int[]{100};`, it reassigns only its local copy of that reference to a new array object, leaving the original array in `main` untouched. On the Oracle Java Foundations 1Z0-811 exam, this concept frequently appears in questions testing your understanding of how arrays are passed to methods, often as a trick where candidates mistakenly think the original array is modified. The common trap is confusing reassigning the local reference with modifying the object’s contents—if the method had changed an element like `arr[0] = 100`, the original would have changed. Remember: you can change the object’s state through a reference, but you cannot change which object the caller’s reference points to. Memory tip: “Reassign the pointer, lose the changer; change the contents, keep the anchor.”
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.
Exhibit
Refer to the exhibit.
public class ArrayTest {
public static void main(String[] args) {
int[] arr = new int[3];
arr[0] = 5;
arr[1] = 10;
arr[2] = 15;
modify(arr);
System.out.println(arr[0]);
}
public static void modify(int[] a) {
a = new int[3];
a[0] = 100;
}
}
Refer to the exhibit.
public class ArrayTest {
public static void main(String[] args) {
int[] arr = new int[3];
arr[0] = 5;
arr[1] = 10;
arr[2] = 15;
modify(arr);
System.out.println(arr[0]);
}
public static void modify(int[] a) {
a = new int[3];
a[0] = 100;
}
}
A
5
The original array is not modified; the method reassigned the reference.
B
0
Why wrong: Not the initial value.
C
Compilation error: cannot assign new array to parameter
Why wrong: Parameters can be reassigned inside the method.
D
100
Why wrong: The modification applies to the new local array, not the original.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
5
Option A is correct because the method `modifyArray` receives a reference to the array, and the assignment `arr = new int[]{100};` changes the local reference `arr` to point to a new array object. The original array in `main` remains unchanged, so `arr[0]` still prints 5. Java passes object references by value, meaning the reference itself is copied, and reassigning the local reference does not affect the caller's reference.
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.
✓
5
Why this is correct
The original array is not modified; the method reassigned the reference.
Related concept
Read the scenario before looking for a memorised answer.
✗
0
Why it's wrong here
Not the initial value.
✗
Compilation error: cannot assign new array to parameter
Why it's wrong here
Parameters can be reassigned inside the method.
✗
100
Why it's wrong here
The modification applies to the new local array, not the original.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Oracle often tests the distinction between modifying an object's state (which affects the caller) versus reassigning the reference (which does not), and the trap here is that candidates mistakenly think reassigning the parameter changes the original array, leading them to choose option D.
Detailed technical explanation
How to think about this question
In Java, all object references are passed by value. When `modifyArray` is called, a copy of the reference to the original array is passed. Inside the method, `arr = new int[]{100};` creates a new array object and assigns its reference to the local copy, leaving the original reference in `main` unchanged. This is a common source of confusion because modifying the array's elements (e.g., `arr[0] = 100;`) would affect the original array, but reassigning the reference does not. In real-world code, this distinction is critical when designing methods that should or should not mutate caller data.
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.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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: 5 — Option A is correct because the method `modifyArray` receives a reference to the array, and the assignment `arr = new int[]{100};` changes the local reference `arr` to point to a new array object. The original array in `main` remains unchanged, so `arr[0]` still prints 5. Java passes object references by value, meaning the reference itself is copied, and reassigning the local reference does not affect the caller's reference.
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.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.