SCJP Java OOP and Inheritance 2

Question 1

Which of the following correctly describes method overloading in Java?

Accepted Answer

Same method name, different parameter list in the same class

Answer

Same method name, same parameter list, different return type

Answer

Same method name, different parameter list in a subclass

Answer

Changing only the return type of a method

Question 2

What is the IS-A relationship in Java OOP?

Accepted Answer

Inheritance

Answer

Composition

Answer

Aggregation

Answer

Encapsulation

Question 3

Which of the following is NOT a valid way to achieve polymorphism in Java?

Accepted Answer

Method overloading at runtime

Answer

Method overriding

Answer

Interface implementation

Answer

Superclass reference to subclass object

Question 4

If class B extends class A and both define `toString()`, which `toString()` is called when `A obj = new B(); System.out.println(obj);`?

Accepted Answer

B's toString()

Answer

A's toString()

Answer

Object's toString()

Answer

Compilation error

Question 5

Which Java feature allows a class to inherit behavior from multiple sources without multiple inheritance of classes?

Accepted Answer

Interfaces with default methods

Answer

Abstract classes

Answer

Enums

Answer

Anonymous classes

Question 6

What is the purpose of the `super` keyword when used inside a method body?

Accepted Answer

To access superclass methods or fields hidden by the subclass

Answer

To create a new superclass instance

Answer

To call a superclass constructor only

Answer

To declare a superclass reference variable