Module 40: Final Quiz & Assessment

📝 Final Quiz

Test your understanding of Core Java by attempting the following quiz. Click the "Show Answer" button to reveal the correct answer.

1. What is the output of the following code?

   int a = 5;
                       int b = ++a + a++;
                       System.out.println(b);

   Show Answer

   Answer: 13 (a becomes 6, so b = 6 + 6 = 12, then a becomes 7)

2. What is the difference between an abstract class and an interface in Java?
   Show Answer

   Answer: Abstract class can have method bodies, fields, constructors; interfaces only contain abstract methods (before Java 8). Interfaces support multiple inheritance.

3. What will be the result of: System.out.println(10/0);?
   Show Answer

   Answer: It throws ArithmeticException: / by zero.

4. Can we override static methods in Java?
   Show Answer

   Answer: No, static methods cannot be overridden, only hidden.

5. What collection would you use if you want to maintain insertion order and allow duplicates?
   Show Answer

   Answer: List (e.g., ArrayList, LinkedList).

6. Explain the difference between checked and unchecked exceptions.
   Show Answer

   Answer: Checked exceptions are checked at compile time (e.g., IOException), unchecked exceptions occur at runtime (e.g., NullPointerException).

7. How do you serialize an object in Java?
   Show Answer

   Answer: By implementing Serializable interface and using ObjectOutputStream.

8. Which keyword is used to inherit a class in Java?
   Show Answer

   Answer: extends

9. What is the purpose of the final keyword?
   Show Answer

   Answer: It restricts usage — final variable cannot be changed, final method cannot be overridden, final class cannot be extended.

10. Write a for-each loop to print all items in an ArrayList of Strings.
    Show Answer

    for (String item : list) {
                          System.out.println(item);
                        }

✅ Instructions

• Attempt all quiz questions honestly without searching online initially
• Note down your answers and reveal solutions to validate your understanding
• Review any incorrect answers to reinforce learning
• Complete the final assessment to validate your learning

🎓 Final Note

You've completed the Core Java Beginner Course. Practicing regularly and taking on real-world problems will cement your skills and prepare you for advanced Java topics and job roles.