Java Array Coding Questions and Answers

🎓 Top 15 Udemy Courses (80-90% Discount): My Udemy Courses - Ramesh Fadatare — All my Udemy courses are real-time and project oriented courses.

▶️ Subscribe to My YouTube Channel (178K+ subscribers): Java Guides on YouTube

▶️ For AI, ChatGPT, Web, Tech, and Generative AI, subscribe to another channel: Ramesh Fadatare on YouTube

Welcome to the Java Array Coding Quiz. In this quiz, we present 10 coding MCQ questions to test your coding knowledge on the Java Array topic. Each question has a correct and brief explanation.

1. What is the output of the following Java code snippet?

int[] array = {1, 2, 3, 4, 5};
System.out.println(array[2]);

a) 1

b) 2

c) 3

d) 4

Answer:

c) 3

Explanation:

Arrays in Java are zero-indexed. array[2] refers to the third element in the array, which is 3.

2. What does this Java code snippet output?

int[] numbers = new int[5];
System.out.println(numbers[3]);

a) 0

b) 3

c) 4

d) Null

Answer:

a) 0

Explanation:

In Java, integer arrays are initialized with default values of 0 for each element. numbers[3] refers to the fourth element, which is 0.

3. Identify the output of the following code:

int[] nums = {1, 2, 3, 4, 5};
for (int i = 0; i < nums.length; i++) {
    nums[i] = nums[i] * 2;
}
System.out.println(nums[2]);

a) 3

b) 4

c) 6

d) 8

Answer:

c) 6

Explanation:

The loop doubles each element of the array. So, nums[2], which was initially 3, becomes 6.

4. What will be printed by this Java code?

int[] array = new int[]{1, 2, 3, 4, 5};
System.out.println(array[array.length - 1]);

a) 1

b) 4

c) 5

d) An error

Answer:

c) 5

Explanation:

array.length is 5, so array[array.length - 1] is array[4], which is the last element of the array, 5.

5. What does this code snippet output?

int[][] matrix = {{1, 2}, {3, 4}, {5, 6}};
System.out.println(matrix[1][1]);

a) 2

b) 3

c) 4

d) 6

Answer:

c) 4

Explanation:

matrix[1][1] accesses the second element of the second array, which is 4.

6. What is the result of executing this code?

int[] numbers = {1, 2, 3, 4, 5};
System.out.println(numbers[numbers.length]);

a) 1

b) 5

c) An ArrayIndexOutOfBoundsException

d) Null

Answer:

c) An ArrayIndexOutOfBoundsException

Explanation:

Accessing numbers[numbers.length] attempts to access an index outside the bounds of the array, resulting in an ArrayIndexOutOfBoundsException.

7. What will the following Java code snippet output?

int[] array = {1, 2, 3, 4, 5};
int[] anotherArray = array;
anotherArray[0] = 10;
System.out.println(array[0]);

a) 1

b) 10

c) 2

d) An error

Answer:

b) 10

Explanation:

anotherArray is a reference to the same array as the array. Changing an element via anotherArray will affect the array as well.

8. What does the following code snippet print?

int[] numbers = {1, 2, 3, 4, 5};
int sum = 0;
for (int number : numbers) {
    sum += number;
}
System.out.println(sum);

a) 10

b) 15

c) 20

d) 25

Answer:

b) 15

Explanation:

This code calculates the sum of all elements in the array, which is 15.

9. Determine the output of this Java code:

int[] values = new int[3];
values[0] = 10;
values[1] = 20;
System.out.println(values[2]);

a) 0

b) 10

c) 20

d) Null

Answer:

a) 0

Explanation:

The array is initialized with default integer values (0). Since values[2] is not explicitly set, it remains 0.

10. What is the result of the following code snippet?

int[] arr = {1, 2, 3, 4, 5};
int x = arr[1] + arr[4];
System.out.println(x);

a) 3

b) 6

c) 7

d) 9

Answer:

c) 7

Explanation:

arr[1] is 2 and arr[4] is 5. Their sum, 2 + 5, is 7.

My Top and Bestseller Udemy Courses. The sale is going on with a 70 - 80% discount. The discount coupon has been added to each course below:

Build REST APIs with Spring Boot 4, Spring Security 7, and JWT

🆕 High-Demand 80–90% OFF

[NEW] Learn Apache Maven with IntelliJ IDEA and Java 25

🆕 High-Demand 80–90% OFF

ChatGPT + Generative AI + Prompt Engineering for Beginners

🚀 Trending Now 80–90% OFF

Spring 7 and Spring Boot 4 for Beginners (Includes 8 Projects)

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Building Real-Time REST APIs with Spring Boot - Blog App

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Building Microservices with Spring Boot and Spring Cloud

🌟 Top Rated 80–90% OFF
Available in Udemy for Business

Java Full-Stack Developer Course with Spring Boot and React JS

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Build 5 Spring Boot Projects with Java: Line-by-Line Coding

🌟 Top Rated 80–90% OFF

Testing Spring Boot Application with JUnit and Mockito

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Spring Boot Thymeleaf Real-Time Web Application - Blog App

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Master Spring Data JPA with Hibernate

🔥 Bestseller 80–90% OFF
Available in Udemy for Business

Spring Boot + Apache Kafka Course - The Practical Guide

🎓 Student Favorite 80–90% OFF
Available in Udemy for Business

Java Testing: Mastering JUnit 5 Framework

🆕 New 80–90% OFF

Reactive Programming in Java: Spring WebFlux and Testing

🌟 Top Rated 80–90% OFF

Spring Boot + RabbitMQ Course - The Practical Guide

🌟 Top Rated 80–90% OFF
Available in Udemy for Business

Functional Programming in Java (Includes Java Collections)

🎓 Student Favorite 80–90% OFF

ChatGPT for Java Developers: Boost Your Productivity with AI

🚀 Trending Now 80–90% OFF