AP CSA Inheritance and Polymorphism

Question 1

What keyword does a subclass use to inherit from a superclass in Java?

Accepted Answer

extends

Answer

implements

Answer

inherits

Answer

super

Question 2

What does it mean to override a method in Java?

Accepted Answer

A subclass provides its own implementation of a method defined in the superclass

Answer

A method calls itself recursively

Answer

A class defines two methods with the same name

Answer

A method is declared but not implemented

Question 3

What keyword is used to call the superclass constructor from a subclass constructor?

Accepted Answer

super()

Answer

this()

Answer

parent()

Answer

base()

Question 4

Which OOP principle allows a subclass object to be used wherever a superclass reference is expected?

Accepted Answer

Polymorphism

Answer

Encapsulation

Answer

Abstraction

Answer

Overloading

Question 5

What is the difference between method overriding and method overloading?

Accepted Answer

Overriding redefines a superclass method; overloading defines multiple methods with the same name but different parameters

Answer

Overriding uses different parameter lists; overloading uses the same parameters

Answer

They are the same thing

Answer

Overloading only works in subclasses

Question 6

What is the purpose of the `@Override` annotation in Java?

Accepted Answer

It tells the compiler to verify the method actually overrides a superclass method

Answer

It makes the method run faster

Answer

It prevents the method from being overridden further

Answer

It marks the method as abstract