Java Programming - MCQ Practice Questions

Consider a scenario where class B extends class A. If class A has a constructor with parameters, what must class B do?

What is the relationship between an abstract class and an interface in Java 8+?

What does the following code output? class A { static void display() { System.out.println("A"); } } class B extends A { static void display() { System.out.println("B"); } } public class Test { public static void main(String[] args) { A ref = new B(); ref.display(); } }

Which of the following is true about interface default methods?

A real-world scenario: You're designing a banking system. Should you use an abstract class or interface for 'Account'?

What happens with exception handling in method overriding?

Which of the following correctly demonstrates composition over inheritance?

What is the output of the following code? interface I1 { default void show() { System.out.println("I1"); } } interface I2 { default void show() { System.out.println("I2"); } } class C implements I1, I2 { public void show() { I1.super.show(); } public static void main(String[] args) { new C().show(); } }

In a legacy system, you find code with very deep inheritance hierarchy (5+ levels). What design problem does this indicate?

What is the access modifier of members declared in an interface?

What is the default access modifier for class members in Java if not explicitly specified?

Which keyword is used to prevent a class from being subclassed?

Can you instantiate an interface in Java?

Which of the following demonstrates proper method overloading in Java?

What will happen if you try to override a final method in a subclass?

In Java, which of the following is true about abstract classes?

What is the correct way to call a parent class constructor from a child class?

Which statement about Java interfaces is INCORRECT according to 2024 specifications?

Consider a class hierarchy: Animal -> Dog -> Puppy. A Puppy reference can access which of the following?

What is the output of this code? class Test { static int x = 10; public static void main(String[] args) { System.out.println(x++); } }