Starting Out With Java Tony Gaddis - Chapter 10

Front 1

In an inheritance relationship, this is the general class. a. subclass b. superclass c. slave class d. child class

Back 1

1. b

Front 2

In an inheritance relationship, this is the specialized class.a. superclassb. master classc. subclassd. parent class

Back 2

2. c

Front 3

This key word indicates that a class inherits from another class. a. derived b. specialized c. based d. extends

Back 3

3. d

Front 4

A subclass does not have access to these superclass members.a. publicb. privatec. protectedd. all of these

Back 4

4. b

Front 5

This key word refers to an object’s superclass. a. super b. base c. superclass d. this

Back 5

5. a

Front 6

In a subclass constructor, a call to the superclass constructor must __________. a. appear as the very first statement b. appear as the very last statement c. appear between the constructor’s header and the opening brace d. not appear

Back 6

6. a

Front 7

The following is an explicit call to the superclass’s default constructor.a. default();b. class();c. super();d. base();

Back 7

7. c

Front 8

A method in a subclass that has the same signature as a method in the superclass is anexample of __________.a. overloadingb. overriding c. compositiond. an error

Back 8

8. b

Front 9

A method in a subclass having the same name as a method in the superclass but a differentsignature is an example of __________.a. overloadingb. overridingc. compositiond. an error

Back 9

9. a

Front 10

These superclass members are accessible to subclasses and classes in the same package.a. privateb. publicc. protectedd. all of these

Back 10

10. c

Front 11

All classes directly or indirectly inherit from this class.a. Objectb. Superc. Rootd. Java

Back 11

11. a

Front 12

With this type of binding, the Java Virtual Machine determines at runtime which method to call, depending on the type of the object that a variable references. a. static b. early c. flexible d. dynamic

Back 12

12. d

Front 13

This operator can be used to determine whether a reference variable references an object of a particular class. a. isclass b. typeof c. instanceof d. isinstance

Back 13

13. c

Front 14

When a class implements an interface, it must __________.

a. overload all of the methods listed in the interface b. provide all of the nondefault methods that are listed in the interface, with the exact signatures and return types specified c. not have a constructor d. be an abstract class

Back 14

14. b

Front 15

Fields in an interface are __________.a. finalb. staticc. both final and staticd. not allowed

Back 15

15. c

Front 16

Abstract methods must be __________.a. overriddenb. overloadedc. deleted and replaced with real methodsd. declared as private

Back 16

16. a

Front 17

Abstract classes cannot __________.a. be used as superclassesb. have abstract methodsc. be instantiatedd. have fields

Back 17

17. c

Front 18

You use the __________ operator to define an anonymous inner class.a. classb. innerc. newd. anonymous

Front 19

An anonymous inner class must __________.a. be a superclassb. implement an interfacec. extend a superclassd. either b or c.

Front 20

A functional interface is an interface with __________.a. only one abstract method.b. no abstract methods.c. only private methods.d. no name

Front 21

You can use a lambda expression to instantiate an object that __________. a. that has no constructor. b. extends any superclass. c. implements a functional interface d. does not implement an interface.

Front 22

True or False: Constructors are not inherited.

Back 22

True

Front 23

True or False: In a subclass, a call to the superclass constructor can only be written in the subclass constructor.

Back 23

True

Front 24

True or False: If a subclass constructor does not explicitly call a superclass constructor, Java will not call any of the superclass’s constructors.

Back 24

False

Front 25

True or False: An object of a superclass can access members declared in a subclass.

Back 25

False

Front 26

True or False: The superclass constructor always executes before the subclass constructor.

Back 26

True

Front 27

True or False: When a method is declared with the final modifier, it must be overridden in a subclass.

Back 27

False

Front 28

True or False: A superclass has a member with package access. A class that is outside the superclass’s package but inherits from the superclass can access the member.

Back 28

False

Front 29

True or False: A superclass reference variable can reference an object of a subclass that extends the superclass

Back 29

True

Front 30

True or False: A subclass reference variable can reference an object of the superclass.

Back 30

False

Front 31

True or False: When a class contains an abstract method, the class cannot be instantiated.

Back 31

True

Front 32

True or False: A class may only implement one interface.

Back 32

False

Front 33

True or False: By default all members of an interface are public

Back 33

True

Front 34

// Superclass

public class Vehicle{ (Member declarations . . .)}

// Subclass

public class Car expands Vehicle{ (Member declarations . . .)}

Back 34

The Car classheader should use the word extendsinstead of expands.

Front 35

// Superclass

public class Vehicle{ private double cost; (Other methods . . .)}

// Subclass

public class Car extends Vehicle{ public Car(double c) { cost = c; }}

Back 35

The Car class constructor cannot access the Vehicle class's cost field.

Front 36

// Superclass

public class Vehicle{ private double cost; public Vehicle(double c) { cost = c; } (Other methods . . .)}

// Subclass

public class Car extends Vehicle

{ private int passengers; public Car(int p) { passengers = c; } (Other methods . . .)}

Back 36

Because the Vehicle class does not have a default constructor or a no-arg constructor, the Car class constructor must call the Vehicle class constructor.

Front 37

// Superclass

public class Vehicle{ public abstract double getMilesPerGallon(); (Other methods . . .)}

// Subclass

public class Car extends Vehicle{ private int mpg; public int getMilesPerGallon(); { return mpg; } (Other methods . . .)}

Back 37

The getMilesPerGallon method in the Car class should return a double.

Front 38

What is an “is-a” relationship?

Back 38

When an “is a” relationship exists between objects, it means that the specialized object has all of the characteristics of the general object, plus additional characteristics that make it special.

Front 39

A program uses two classes: Animal and Dog. Which class is the superclass and which is the subclass?

Back 39

The superclass is Animal and the subclass is Dog.

Front 40

What is the superclass and what is the subclass in the following line? public class Pet extends Dog

Back 40

Dog is the superclass and Pet is the subclass.

Front 41

What is the difference between a protected class member and a private class member?

Back 41

A protected member of a class may be directly accessed by methods of the same class or methods of a subclass. In addition, and this is how protected members are different from private members, protected members may be accessed by methods of any class that are in the same package as the protected member’s class. A protected member is not quite private, because it may be accessed by some methods outside the class.

Front 42

Can a subclass ever directly access the private members of its superclass?

Back 42

No.

Front 43

Which constructor is called first, that of the subclass or the superclass?

Back 43

The superclass.

Front 44

What is the difference between overriding a superclass method and overloading a superclass method?

Back 44

Overloading is when a method has the same name as one or more other methods, but a different parameter list. Although overloaded methods have the same name, they have different signatures. When a method overrides another method, however, they both have the same signature.

Front 45

Reference variables can be polymorphic. What does this mean?

Back 45

A superclass reference variable can reference objects of classes that inherit from the superclass.

Front 46

When does dynamic binding take place?

Back 46

At runtime.

Front 47

What is an abstract method?

Back 47

An abstract method is a method that appears in a superclass, but expects to be overridden in a subclass. An abstract method has only a header and no body.

Front 48

What is an abstract class?

Back 48

11. An abstract class is not instantiated itself, but serves as a superclass for other classes. The abstract class represents the generic or abstract form of all the classes that inherit from it.

Front 49

What are the differences between an abstract class and an interface?

Back 49

A class can inherit from only one superclass, but Java allows a class to implement multiple interfaces.

Front 50

When you instantiate an anonymous inner class, the class must do one of two things. What are they?

Back 50

NA

Front 51

What is a functional interface?

Back 51

NA

Front 52

What is a lambda expression?

Back 52

Anonymous Classes. Before lambda expressions, anonymous inner classes were an option. For example, an interface ( MyTest.java ) written with one test method that returns a boolean (a functional interface) is a possible solution. The search criteria could be passed when the method is called.Ref#Google