Chapter 9

Question 1

Employing inheritance reduces errors because

Answer 1

Baby of the methods a subclass needs have already been used and tested

Question 2

A base class can also be called a

Answer 2

Superclass

Question 3

What is an example of a parent class/child class relationship?

Answer 3

BodyOfWater/River

Question 4

A class named Building has public, no static method named getFloors(). If School is a child class of Building, and modelHigh is an object of type School, is modelHigh.getFloors() valid?

Answer 4

Yes

Question 5

When a subclass method has the same name and argument types as a super class method, the subclass method ______ the superclass method.

Answer 5

Overrides

Question 6

When you instantiate an object that is a member of a subclass, the ______ constructor executes first.

Answer 6

Parent class

Question 7

If you only constructor in a superclass requires arguments, its subclass

Answer 7

Must contain a constructor

Question 8

A child class Motorcycle extends a parent class Vehicle. Each class constructor requires one String argument. The Motorcycle class constructor can call the Vehicle class constructor with the statement

Answer 8

Super(“Suzuki”);

Question 9

If you create a data field or method that is ______, it can be used within its own class or in any classes extended from that class.

Answer 9

Public or protected

Question 10

You use a _____ method access specifier when you create methods for which you want to prevent overriding in extended classes.

Answer 10

Final

Question 11

When a parent class contains a static method, child classes ______ override it.

Answer 11

Cannot

Question 12

Abstract classes differ from other classes in that you

Answer 12

Cannot instantiate objects from them.

Question 13

An abstract class Dwelling has two subclasses, SingleFamily and MultiFamily. None of the constructors for these classes requires any arguments. Is SingleFamily myHome = new SingleFamily() valid?

Answer 13

Yes

Question 14

An abstract class Employee has two subclasses, Permanent and Temporary. The Employee class contains an abstract method named setType(). Before you can instantiate Permanent and Temporary objects, what is true?

Answer 14

You must code statements for the setType() method within both the Permanent and Temporary classes.

Question 15

Super class ________ contain abstract methods.

Answer 15

Can

Question 16

When you create a ______ in Java, you create a variable name in which you can hold the memory address of an object.

Answer 16

Reference

Question 17

An application’s ability to select the correct subclass method to execute is known as ________ method binding.

Answer 17

Dynamic

Question 18

You ________ override the toString() method in any class you create.

Answer 18

Can

Question 19

The Object class equals() method takes

Answer 19

One argument

Question 20

The alternative to multiple inheritance in Java is known as a(n)

Answer 20

Interface