Question 1

When declared as protected, which statement is true about the access to data in an object?

Accepted Answer

A) The data is accessible only by that class's methods and by all of its subclasses 
B) The data is accessible only by that class's methods, by all of its subclasses, and by methods in classes within the same package. 
C) The data is accessible only by that class's methods. 
D) The data is accessible by any class. 
A) The data is accessible only by that class's methods and by all of its subclasses 
B) The data is accessible only by that class's methods, by all of its subclasses, and by methods in classes within the same package. 
C) The data is accessible only by that class's methods. 
D) The data is accessible by any class.

Question 2

Consider the hierarchy of classes shown below.   What is the direct superclass of the class ScriptedShow?

Accepted Answer

A) Comedy 
B) RealityShow 
C) Object 
D) TelevisionShow 
A) Comedy 
B) RealityShow 
C) Object 
D) TelevisionShow

Question 3

Consider the following code snippet:   What does this code do?

Accepted Answer

A) It invokes the constructor of the Vehicle class from within the constructor of the Motorcycle class. 
B) It invokes the constructor of the Motorcycle class from within the constructor of the Vehicle class. 
C) It invokes a private method of the Vehicle class from within a method of the Motorcycle class. 
D) This code will not compile. 
A) It invokes the constructor of the Vehicle class from within the constructor of the Motorcycle class. 
B) It invokes the constructor of the Motorcycle class from within the constructor of the Vehicle class. 
C) It invokes a private method of the Vehicle class from within a method of the Motorcycle class. 
D) This code will not compile.

Question 4

Consider the following inheritance hierarchy diagram:   Which of the following statements is correct?

Accepted Answer

A) Auto class inherits from LandVehicle class, 
and LandVehicle class inherits from Vehicle class. 
B) Auto class inherits from LandVehicle class, and Vehicle class inherits from LandVehicle class. 
C) LandVehicle class inherits from Auto class, and LandVehicle class inherits from Vehicle class. 
D) LandVehicle class inherits from Auto class, and Vehicle class inherits from LandVehicle class. 
A) Auto class inherits from LandVehicle class, 
and LandVehicle class inherits from Vehicle class. 
B) Auto class inherits from LandVehicle class, and Vehicle class inherits from LandVehicle class. 
C) LandVehicle class inherits from Auto class, and LandVehicle class inherits from Vehicle class. 
D) LandVehicle class inherits from Auto class, and Vehicle class inherits from LandVehicle class.

Question 5

You are creating a Motorcycle class which is supposed to be a subclass of the Vehicle class.Which of the following class declaration statements will accomplish this?

Accepted Answer

A) public class Motorcycle extends Vehicle 
B) public class Motorcycle implements Vehicle 
C) public class Motorcycle interfaces Vehicle 
D) public class Motorcycle inherits Vehicle 
A) public class Motorcycle extends Vehicle 
B) public class Motorcycle implements Vehicle 
C) public class Motorcycle interfaces Vehicle 
D) public class Motorcycle inherits Vehicle

Question 6

Consider the following code snippet:   Which of the following statements is correct?

Accepted Answer

A) The subclass is shadowing a superclass method. 
B) The subclass is overloading a superclass method. 
C) The subclass is overriding a superclass method. 
D) This code will not compile. 
A) The subclass is shadowing a superclass method. 
B) The subclass is overloading a superclass method. 
C) The subclass is overriding a superclass method. 
D) This code will not compile.

Question 7

Which of the following statements about comparing objects is correct?

Accepted Answer

A) The purpose of the equals method is to compare whether two references are to the same object. 
B) The purpose of the equals method is to compare whether two objects have the same contents. 
C) The == operator is used to compare whether two objects have the same contents. 
D) For objects other than Object, the equals method and the == operator always perform the same actions. 
A) The purpose of the equals method is to compare whether two references are to the same object. 
B) The purpose of the equals method is to compare whether two objects have the same contents. 
C) The == operator is used to compare whether two objects have the same contents. 
D) For objects other than Object, the equals method and the == operator always perform the same actions.

Question 8

Consider the Counter class below.

Accepted Answer

A) true 
B) false 
C) nothing since equals is not defined for Counter 
D) a syntax error 
A) true 
B) false 
C) nothing since equals is not defined for Counter 
D) a syntax error

Question 9

Consider the following code snippet:   Which of the following statements is correct?

Accepted Answer

A) The Auto class overrides the setVehicleClass method. 
B) The Vehicle class overrides the setVehicleClass method. 
C) The Auto class overloads the setVehicleClass method. 
D) The Vehicle class overloads the setVehicleClass method. 
A) The Auto class overrides the setVehicleClass method. 
B) The Vehicle class overrides the setVehicleClass method. 
C) The Auto class overloads the setVehicleClass method. 
D) The Vehicle class overloads the setVehicleClass method.

Question 10

Consider the classes shown below:

Accepted Answer

A) Line 1 only 
B) Line 2 only 
C) Lines 1 and 2 
D) Neither line will compile without error 
A) Line 1 only 
B) Line 2 only 
C) Lines 1 and 2 
D) Neither line will compile without error

Question 11

All hamsters are rodents and all rodents are mammals.What hierarchy best captures this information?

Accepted Answer

A) Hamster is a superclass of Rodent and Rodent is a superclass of Mammal 
B) Mammal is a superclass of Rodent and Rodent is a superclass of Hamster 
C) Mammal is a superclass of Rodent and Hamster 
D) Hamster is a superclass of Rodent and Mammal 
A) Hamster is a superclass of Rodent and Rodent is a superclass of Mammal 
B) Mammal is a superclass of Rodent and Rodent is a superclass of Hamster 
C) Mammal is a superclass of Rodent and Hamster 
D) Hamster is a superclass of Rodent and Mammal

Question 12

Which of the following statements is true about using the reserved word super to call a superclass constructor?

Accepted Answer

A) The call must use the keyword super followed by a period and a method name. 
B) The call must use the keyword super with no arguments. 
C) The call must be the last line of the subclass constructor. 
D) The call must be the first line of the subclass constructor. 
A) The call must use the keyword super followed by a period and a method name. 
B) The call must use the keyword super with no arguments. 
C) The call must be the last line of the subclass constructor. 
D) The call must be the first line of the subclass constructor.

Question 13

In designing an inheritance hierarchy it is helpful first to list classes that are part of the hierarchy and then organize those classes via an inheritance diagram.Once this has been done, what is the next step in the design?

Accepted Answer

A) Determine common responsibilities among the classes. 
B) Decide which methods should be overridden. 
C) Declare the public interface of each class. 
D) Define and implement constructors and methods. 
A) Determine common responsibilities among the classes. 
B) Decide which methods should be overridden. 
C) Declare the public interface of each class. 
D) Define and implement constructors and methods.

Question 14

Insert the missing code in the following code fragment.This fragment is intended to call the Vessel class's method.

Accepted Answer

A) SpeedBoat.vesselLength(26.0); 
B) Vessel.vesselLength(26.0); 
C) vesselLength = 26.0; 
D) setVesselClass(26.0); 
A) SpeedBoat.vesselLength(26.0); 
B) Vessel.vesselLength(26.0); 
C) vesselLength = 26.0; 
D) setVesselClass(26.0);

Question 15

Which class represents a more specific entity in an inheritance hierarchy?

Accepted Answer

A) Default class 
B) Superclass 
C) Subclass. 
D) Inheritance class. 
A) Default class 
B) Superclass 
C) Subclass. 
D) Inheritance class.

Question 16

Consider the following class hierarchy:   What is wrong with this class hierarchy definition?

Accepted Answer

A) Nothing is wrong with the code. 
B) There should be more subclasses of the Shape class than just Triangle. 
C) There cannot be any subclasses of the Shape class. 
D) It is not possible to use super in the Triangle constructor. 
A) Nothing is wrong with the code. 
B) There should be more subclasses of the Shape class than just Triangle. 
C) There cannot be any subclasses of the Shape class. 
D) It is not possible to use super in the Triangle constructor.

Question 17

Which of the following is true regarding inheritance?

Accepted Answer

A) When creating a subclass, all methods of the superclass must be overridden. 
B) When creating a subclass, no methods of a superclass can be overridden. 
C) A superclass can force a programmer to override a method in any subclass created from it. 
D) A superclass cannot prevent a programmer from overriding a method in any subclass created from it. 
A) When creating a subclass, all methods of the superclass must be overridden. 
B) When creating a subclass, no methods of a superclass can be overridden. 
C) A superclass can force a programmer to override a method in any subclass created from it. 
D) A superclass cannot prevent a programmer from overriding a method in any subclass created from it.

Question 18

To ensure that an instance variable can only be accessed by the class that declared it, how should the variable be declared?

Accepted Answer

A) public 
B) private 
C) protected 
D) final 
A) public 
B) private 
C) protected 
D) final

Question 19

Consider the following code snippet:   Which of the following statements is correct?

Accepted Answer

A) The subclass is shadowing a superclass method. 
B) The subclass is overloading a superclass method. 
C) The subclass is overriding a superclass method. 
D) The subclass is defining its own distinct method. 
A) The subclass is shadowing a superclass method. 
B) The subclass is overloading a superclass method. 
C) The subclass is overriding a superclass method. 
D) The subclass is defining its own distinct method.

Question 20

Consider the following code snippet:   Which of the following statements is correct?

Accepted Answer

A) An object of type Programmer can call the setDepartment method of the Employee class on itself. 
B) An object of type Employee can call the setProjectName method on itself. 
C) The Employee class's setDepartment method overrides the Programmer class's setDepartment method. 
D) An object of type Employee can call the setDepartment method of the Programmer class on itself. 
A) An object of type Programmer can call the setDepartment method of the Employee class on itself. 
B) An object of type Employee can call the setProjectName method on itself. 
C) The Employee class's setDepartment method overrides the Programmer class's setDepartment method. 
D) An object of type Employee can call the setDepartment method of the Programmer class on itself.

Exam 9: Inheritance

When declared as protected, which statement is true about the access to data in an object?

Consider the hierarchy of classes shown below. What is the direct superclass of the class ScriptedShow?

Consider the following code snippet: What does this code do?

Consider the following inheritance hierarchy diagram: Which of the following statements is correct?

You are creating a Motorcycle class which is supposed to be a subclass of the Vehicle class.Which of the following class declaration statements will accomplish this?

Consider the following code snippet: Which of the following statements is correct?

Which of the following statements about comparing objects is correct?

Consider the Counter class below.

Consider the following code snippet: Which of the following statements is correct?

Consider the classes shown below:

All hamsters are rodents and all rodents are mammals.What hierarchy best captures this information?

Which of the following statements is true about using the reserved word super to call a superclass constructor?

In designing an inheritance hierarchy it is helpful first to list classes that are part of the hierarchy and then organize those classes via an inheritance diagram.Once this has been done, what is the next step in the design?

Insert the missing code in the following code fragment.This fragment is intended to call the Vessel class's method.

Which class represents a more specific entity in an inheritance hierarchy?

Consider the following class hierarchy: What is wrong with this class hierarchy definition?

Which of the following is true regarding inheritance?

To ensure that an instance variable can only be accessed by the class that declared it, how should the variable be declared?

Consider the following code snippet: Which of the following statements is correct?

Consider the following code snippet: Which of the following statements is correct?

Introduction

Using Objects

Implementing Classes

Fundamental Data Types

Decisions

Loops

Arrays and Array Lists

Designing Classes

Interfaces

Input/Output and Exception Handling

Object-Oriented Design

Recursion

Sorting and Searching

The Java Collections Framework

Basic Data Structures

Tree Structures

Generic Classes

Stream Processing

Graphical User Interfaces

Advanced Input/Output

Multithreading

Internet Networking

Relational Databases

XML

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