Deck 10: Introduction to Inheritance

Question 1

The ability to use inheritance in Java makes programs easier to write, ____, and more quickly understood.

A) faster
B) more secure
C) more robust
D) less error prone

Answer 1

D

Question 2

If a programming language does not support ____, the language is not considered object-oriented.

A) syntax
B) applets
C) loops
D) polymorphism

Answer 2

D

Question 3

The class used as a basis for inheritance is the ____ class.

A) child
B) extends
C) base
D) derived

Answer 3

C

Question 4

When a protected data field or method is created, it can be used within its own class or in any classes extended from that class; but it cannot be used by outside classes.

Question 5

You use the keyword ____ to achieve inheritance in Java.

A) inherit
B) extends
C) super
D) public

Question 6

Java's Math class is an example of a protected class.

Question 7

Superclasses can be distinguished from their subclasses because a subclass is generally smaller than a superclass; it usually has fewer fields and methods.

Question 8

An error is generated by the compiler when you attempt to override a static method with a nonstatic method.

Question 9

____ is the principle that allows you to apply your knowledge of a general category to more specific objects.

A) Inheritance
B) Polymorphism
C) Encapsulation
D) Override

Question 10

If a superclass contains only constructors that require arguments, you do not need to create a subclass constructor.

Question 11

When you use the method name with a child object, the parent's version of the method is used.

Question 12

A class diagram consists of a rectangle divided into three sections.

Question 13

By convention, a class diagram contains the ____ following each attribute or method.

A) data field
B) argument
C) data type
D) class

Question 14

____ polymorphism is the ability of one method name to work appropriately for different subclass objects of the same parent class.

A) Subtype
B) Name
C) Supertype
D) Override

Question 15

Conventionally, arrows used in a ____ to show inheritance relationships extend from the descendant class and point to the one from which it descends.

A) method diagram
B) UML diagram
C) virtual method call
D) composition

Question 16

In a UML diagram, minus signs are inserted in front of each private field or method, and plus signs are inserted in front of each public field or method.

Question 17

It is useful to override the parent class members when the superclass data fields and methods are not completely appropriate for the subclass objects.

Question 18

Sometimes the superclass data fields and methods are not entirely appropriate for the subclass objects; in these cases, you want to ____ the parent class members.

A) negate
B) overrule
C) override
D) hide

Question 19

When you create a class by making it inherit from another class, you are provided with data fields and ____ automatically.

A) fonts
B) methods
C) class names
D) arrays

Question 20

A static method cannot be overridden in a subclass.

Question 21

An advantage to making a method ____________________ is that the compiler knows there will be only one version of the method.

Question 22

Usually, the subclass constructor only needs to initialize the ____ that are specific to the subclass.

A) objects
B) data fields
C) methods
D) constructors

Question 23

Which statement correctly declares a sedan object of the Car class?

A) sedan Car = new sedan();
B) sedan Car = new sedan();
C) Car sedan = new Car();
D) new sedan() = Student;

Question 24

You can use the ____ modifier with methods when you don't want the method to be overridden.

A) override
B) access
C) final
D) end

Question 25

In most Java classes, the keyword private precedes each data field, and the keyword ____________________ precedes each method.

Question 26

When you create parent and child classes of your own, the child classes use ____ constructors.

A) two
B) three
C) four
D) six

Question 27

When you employ ____, your data can be altered only by the methods you choose and only in ways that you can control.

A) virtual method calls
B) polymorphism
C) information hiding
D) inlining

Question 28

Using the keyword ____ provides you with an intermediate level of security between public and private access.

A) protected
B) this
C) super
D) secure

Question 29

If jrStudent is an object of Student, which of the following statements will result in a value of true?

A) Student = instanceof jrStudent
B) jrStudent instanceof Student
C) instanceof Student = jrStudent
D) Student instanceof jrStudent

Question 30

Within a subclass, you can think of the keyword ____ as the opposite of super.

A) sub
B) this
C) protected
D) not

Question 31

The classes you create in ____________________ programming languages can inherit data and methods from existing classes.

Question 32

Which of the following statements depicts the valid format to call a superclass constructor from a subclass constructor?

A) superclass(name, score);
B) subclass(name, score);
C) extends(name, score);
D) super(name, score);

Question 33

Which of the following statements will create a class named Red that is based on the class Color?

A) public class Red extends Color
B) public Red class extends Color
C) public Color class expands Red
D) public extend Red class Color

Question 34

The methods in a subclass can use all of the data fields and methods that belong to its parent, with one exception: ____ members of the parent class are not accessible within a child class's methods.

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

Question 35

The term ____________________ means "many forms."

Question 36

When you create a class and do not provide a(n) ____, Java automatically supplies you with a default one.

A) constructor
B) argument
C) header
D) name

Question 37

If a ____ method has the same name as a parent class method and you use the name with a child class object, the child method hides the original.

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

Question 38

You are never aware that ____ is taking place; the compiler chooses to use this procedure to save the overhead of calling a method.

A) information hiding
B) polymorphism
C) overriding
D) inlining

Question 39

You would like to make a member of a class visible in all subclasses regardless of what package they are in. Which one of the following keywords would achieve this?

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

Question 40

Programmers and analysts sometimes use a graphical language to describe classes and object-oriented processes. This language is called ___________________________________.

Question 41

What are virtual method calls?

Question 42

What is the process of inlining and how is it accomplished in Java?

Question 43

Match each term with the correct statement below.
a.information hiding
f.virtual method call
b.inheritance
g.inlining
c.super()
h.class diagram
d.superclass
i.derived class
e.instanceof
Makes a program run faster

Question 44

Match each term with the correct statement below.
a.information hiding
f.virtual method call
b.inheritance
g.inlining
c.super()
h.class diagram
d.superclass
i.derived class
e.instanceof
Inherits from a base class

Question 45

Match each term with the correct statement below.
a.information hiding
f.virtual method call
b.inheritance
g.inlining
c.super()
h.class diagram
d.superclass
i.derived class
e.instanceof
An instance method call

Question 46

Match each term with the correct statement below.
a.information hiding
f.virtual method call
b.inheritance
g.inlining
c.super()
h.class diagram
d.superclass
i.derived class
e.instanceof
Determines whether an object is a member or descendant of a class

Question 47

Write the statement to create a class header with a superclass-subclass relationship, with Vehicle as the superclass and Subaru as the subclass.

Question 48

Match each term with the correct statement below.
a.information hiding
f.virtual method call
b.inheritance
g.inlining
c.super()
h.class diagram
d.superclass
i.derived class
e.instanceof
A mechanism that enables one class to assume both the behavior and the attributes of another class

Question 49

When you instantiate an object that is a member of a subclass, how many constructors are called?

Question 50

Match each term with the correct statement below.
a.information hiding
f.virtual method call
b.inheritance
g.inlining
c.super()
h.class diagram
d.superclass
i.derived class
e.instanceof
A part of UML

Question 51

What happens when you write your own constructor in Java and what must you pay attention to?

Question 52

What is information hiding and how is it used?

Question 53

Match each term with the correct statement below.
a.information hiding
f.virtual method call
b.inheritance
g.inlining
c.super()
h.class diagram
d.superclass
i.derived class
e.instanceof
Must be the first statement in the subclass constructor

Question 54

What does polymorphism mean in Java programming?

Question 55

What is the difference between derived classes and base classes when considering two classes that inherit from each other?

Question 56

How is the keyword protected used?

Question 57

What are the parts of a class diagram and how would you use them?

Question 58

Match each term with the correct statement below.
a.information hiding
f.virtual method call
b.inheritance
g.inlining
c.super()
h.class diagram
d.superclass
i.derived class
e.instanceof
A base class

Question 59

Match each term with the correct statement below.
a.information hiding
f.virtual method call
b.inheritance
g.inlining
c.super()
h.class diagram
d.superclass
i.derived class
e.instanceof
Keeps data private

Question 60

How are real-life examples of inheritance similar to object-oriented programming inheritance?

Question 61

class Animal
{
void myDog()
{
System.out.println("Animal stuff");
}
}
class Dog extends Animal
{
void mydog()
{
System.out.println("Dog stuff");
}
public static void main(String args[])
{
Dog d = new Dog();
d.myDog();
super.myDog();
}
}
The above code gives a compiler error stating that the non-static variable super cannot be
referenced from a static context super.myDog();. Explain why the error occurs and describe what changes you could make for the code to be executable.

Question 62

public class Student
{
private String firstName;
private String lastName;
private String address;
private String username;
public Student(String studentFirstName, String StudentLastName, String studentAddress String studentUsername)
{
firstName = studentFirstName;
lastName = studentLastName;
address = studentAddress;
username = studentUsername;
}
}
public void displayStudentInfo()
{
System.out.println("Name: " + firstName + " " + lastName);
System.out.println("Address: " + address);
System.out.println("Username: " + username);
}
Using the above code, call the constructor to create a new instance of the Student object named joe. The constructor method will take the four string values (first name, last name, address, username) and set the initial state of the Student object to be: firstname = "Joe", lastname = "Jones", address = "123 Oak St.", username = "JJones".

Question 63

class InstanceofDemo
{
public static void main(String[] args)
{
Parent object1 = new Parent();
Parent object2 = new Child();
System.out.println("object1 instanceof Parent: "
+ (obj1 instanceof Parent));
System.out.println("object1 instanceof Child: "
+ (obj1 instanceof Child));
System.out.println("object1 instanceof MyInterface: "
+ (obj1 instanceof MyInterface));
System.out.println("object2 instanceof Parent: "
+ (obj2 instanceof Parent));
System.out.println("object2 instanceof Child: "
+ (obj2 instanceof Child));
System.out.println("object2 instanceof MyInterface: "
+ (obj2 instanceof MyInterface));
}
}
The above code defines a parent class (named Parent), a simple interface (named MyInterface), and a child class (named Child) that inherits from the parent and implements the interface.
Following program execution, what will be the output of the six println statements?

Question 64

class Vehicle {}
public class Car extends Vehicle
{
public static void main(String args[])
{
Vehicle myCar = new Car();
boolean result = myCar instanceof Car;
System.out.println(result);
}
}
The above code uses the instanceof operator to determine whether an object is a member of a class. What will be the output following execution?

Question 65

public class Student
{
private String firstName;
private String lastName;
private String address;
private String username;
public Student(String studentFirstName, String StudentLastName, String studentAddress String studentUsername)
{
firstName = studentFirstName;
lastName = studentLastName;
address = studentAddress;
username = studentUsername;
}
}
Create a method called displayStudentInfo that will display the value of the first name, last name, address, and username objects using println() statements.

Question 66

Using a class named Student, write the statement to create a yearOne object of the Student class.

Question 67

Create a class named Employee with a name and a salary. Make a class named Manager that inherits from Employee with an instance field named department. Supply a toString() method that prints the manager's name, department, and salary. Make another class named Director that inherits from Manager with an instance field named stipendAmount. Supply the toString() method for Director that prints all of its instance variables. Also, write a program named myOutput that instantiates an object of each of the classes and invokes the toString() method of each of the objects.

Question 68

public class Student
{
private String firstName;
private String lastName;
private String address;
private String username;
public Student(String ____, String ____, String ____, String ____)
{
____ = ____;
____ = ____;
____ = ____:
____ = ____;
}
}
In the shaded areas provided, create a constructor that accepts the values of the student's first name, last name, address, and username. Use these values to set the initial state of the object.

Question 69

You have a Student class with a constructor that requires two arguments: a character "F" for Freshman and an integer "2020" for the year. Create a Freshman class that is a subclass of Student with a constructor for Freshman. Include the initial super() statement and include a comment that reads "//Other statements go here".

Question 70

Create a class named Account that contains an integer field for an account number and a double field for an account balance. The class contains a constructor that requires an account number and sets the balance to 0.0. Include a set() method for the balance, a get() method for the account number, and a get() method for the account balance. Create two subclasses named Checking and Savings. Within the Checking class, the get() method should display the String "Checking Account Information", the account number, and the balance. Within the Savings class, add a field to hold the interest rate, and require the Savings constructor to accept an argument for the value of the interest rate. The Savings get() method displays the String "Savings Account Information", the account number, the balance, and the interest.