Java Quiz 29: Working with objects and references

<< Java Quizzes    Green = Easy,  Blue = Normal,  Red = Hard
 01   02   03   04   05   06   07   08   09   10   11   12   13   14   15   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30   31   32   33   By title 

Java Quiz 29: Working with objects and references

Level: Normal

What is the output of the following code?

public class Test
  static Student st = new Student("Emma");
  public static void main(String[] args)
    Student st = new Student("Vera");
    Test ts = new Test(); = st;;
    System.out.print( + ", ");
    System.out.print(new Test();
class Student
  String name;
  public Student(String name)
  { = name;
  public void change(Student student)
    student = new Student("David");
Author: Sar Maroof

Select the correct answer.
a. This program writes “David, Emma” to the standard output.
b. This program writes “David, Vera” to the standard output.
c. This program writes “Vera, Vera” to the standard output.
d. This program writes “Vera, Emma” to the standard output.
e. Runtime error.
f. Compilation error.

Answer explanation

  1. The statement Student st = new Student(“Vera”); assigns the name Vera to the name of the student object st.
  2. The statement = st; assigns the object st to the reference
  3. Remember that the the object is static, which belongs to the class.
  4. The statement; doesn’t change the refernce st, because the value of the of the object st is passed to the method change not its reference.
  5. So, the statements System.out.print( + “, “); and System.out.print(new Test(); write Vera, Vera to the standard output.

The correct answer is: c.

If you found this difficult, you might consider reading my book Java quizmaster for beginners. It is easy to understand, organized to learn Java in 17 days and it guides you to master Java code by solving 105 quizzes and 117 assignments. This book explains each chapter properly before starting with exercises and assignments. It is available on Amazon. See inside the book here!

Please, leave your questions, feedback and suggestions in the comments below! offers a practical method to learn and improve your Java skills. It avoids unnecessary long boring theoretical explanations, but it uses many exercises and quizzes.

Sar Maroof is graduated from HBO Amsterdam "higher professional education". He is a professional computer programming teacher, gives master classes and publishes technical articles. His experience with developing software started from 2001 and he has worked as a software developer for several big as well as small companies and later as a freelancer. He is the author of Java quizmaster and Build a Java application in 7 days.

Books by Sar Maroof


 Subscribe to Sar Maroof's RSS feeds!
 Mail this page to a friend!
 Bookmark this page!

Leave a Reply

Your email address will not be published. Required fields are marked *