Inheritance Quiz

Which of the following is the correct syntax to indicate that class A is a subclass of B?

•  public class B extends A {
•  public A implements B {
•  public class A : super B {
•  public class A extends B {

Consider the following classes:

public class Vehicle {...}

public class Car extends Vehicle {...}

public class SUV extends Car {...}

•  Car c = new SUV();
•  SUV s = new Car();
• Car c = new Vehicle();
• SUV s = new Vehicle():

 Can an object be a subclass of another object?

• Yes---as long as single inheritance is followed.
• No---inheritance is only between classes.
• Only when one has been defined in terms of the other.
• Yes---when one object is used in the constructor of another.

Which of the following is correct syntax for defining a new class Jolt based on the superclass SoftDrink? 

•  class Jolt isa SoftDrink { //additional definitions go here }
• class Jolt implements SoftDrink { //additional definitions go here }
•  class Jolt defines SoftDrink { //additional definitions go here }
• class Jolt extends SoftDrink { //additional definitions go here }

Does a subclass inherit both member variables and methods? 

•  No--only member variables are inherited.
•  No--only methods are inherited.
• Yes--both are inherited.
• Yes--but only one or the other are inherited.

Which of the following is NOT an advantage to using inheritance? 

• Code that is shared between classes needs to be written only once.
• Similar classes can be made to behave consistently.
• Enhancements to a base class will automatically be applied to derived classes.
• One big superclass can be used instead of many little classes.

 What restriction is there on using the super reference in a constructor? 

• It can only be used in the parent's constructor.
•  Only one child class can use it.
• It must be used in the last statement of the constructor.
• It must be used in the first statement of the constructor.

Say that there are three classes: Computer, AppleComputer, and IBMComputer. What are the likely relationships between these classes? 

•  Computer is the superclass, AppleComputer and IBMComputer are subclasses of Computer.
•  IBMComputer is the superclass, AppleComputer and Computer are subclasses of IBMComputer.
•  Computer, AppleComputer and IBMComputer are sibling classes.
• Computer is a superclass, AppleComputer is a subclasses of Computer, and IBMComputer is a sublclas of AppleComputer

A class Animal has a subclass Mammal. Which of the following is true:

• Because of single inheritance, Mammal can have no subclasses.
•  Because of single inheritance, Mammal can have no other parent than Animal
• Because of single inheritance, Animal can have only one subclass.
• Because of single inheritance, Mammal can have no siblings.

Are you ready to Graduate?

• Yes 
• NO
• Let me leave
• I graduated freshman year