Question 1

Declaring a method final means:

Accepted Answer

A)  it will prepare the object for garbage collection. 
B)  it cannot be accessed from outside its class. 
C)  it cannot be overloaded. 
D)  it cannot be overridden. 
A)  it will prepare the object for garbage collection. 
B)  it cannot be accessed from outside its class. 
C)  it cannot be overloaded. 
D)  it cannot be overridden.

Question 2

Polymorphism enables you to:

Accepted Answer

A)  program in the general. 
B)  program in the specific. 
C)  absorb attributes and behavior from previous classes. 
D)  hide information from the user. 
A)  program in the general. 
B)  program in the specific. 
C)  absorb attributes and behavior from previous classes. 
D)  hide information from the user.

Question 3

Which of the following could be used to declare abstract method method1 in abstract class Class1 (method1 returns an int and takes no arguments)?

Accepted Answer

A)  public int method1(); 
B)  public int abstract method1(); 
C)  public abstract int method1(); 
D)  public int nonfinal method1(); 
A)  public int method1(); 
B)  public int abstract method1(); 
C)  public abstract int method1(); 
D)  public int nonfinal method1();

Question 4

The UML distinguishes an interface from other classes by placing the word "interface" in________ above the interface name.

Accepted Answer

A)  italics. 
B)  carets. 
C)  guillemets. 
D)  bold. 
A)  italics. 
B)  carets. 
C)  guillemets. 
D)  bold.

Question 5

Consider the abstract superclass below: 
public abstract class Foo {
Private int a;
Public int b;
Public Foo(int aVal, int bVal) {
A = aVal;
B = bVal;
}
Public abstract int calculate();
}
Any concrete subclass that extends class Foo:

Accepted Answer

A)  Must implement a method called calculate. 
B)  Will not be able to access the instance variable 
C)  Neither (a) nor (b). 
D)  Both (a) and (b). 
A)  Must implement a method called calculate. 
B)  Will not be able to access the instance variable 
C)  Neither (a) nor (b). 
D)  Both (a) and (b).

Question 6

Which of the following statements is false?

Accepted Answer

A)  A class's private helper methods may be called only by the class's other methods 
B)  You cannot declare helper methods in interfaces. 
C)  An interface's private instance methods can be called directly (i.e., without an object reference) only by the interface's other instance methods. 
D)  An interface's private static methods can be called by any of the interface's instance or static methods. 
A)  A class's private helper methods may be called only by the class's other methods 
B)  You cannot declare helper methods in interfaces. 
C)  An interface's private instance methods can be called directly (i.e., without an object reference) only by the interface's other instance methods. 
D)  An interface's private static methods can be called by any of the interface's instance or static methods.

Question 7

Aclass that implements an interface but does not declare all of the interface's methods must be declared ________.

Accepted Answer

A)  public. 
B)  interface. 
C)  abstract. 
D)  final. 
A)  public. 
B)  interface. 
C)  abstract. 
D)  final.

Question 8

Every object in Java knows its own class and can access this information through method .

Accepted Answer

A)  getClass. 
B)  getInformation. 
C)  objectClass. 
D)  objectInformation. 
A)  getClass. 
B)  getInformation. 
C)  objectClass. 
D)  objectInformation.

Question 9

Which of the following does not complete the sentence correctly? 
An interface _______________.

Accepted Answer

A)  forces classes that implement it to declare all the abstract interface methods. 
B)  can be used in place of an abstract class when there is no default implementation to inherit. 
C)  is declared in a file by itself and is saved in a file with the same name as the interface followed by the .java extension. 
D)  can be instantiated. 
A)  forces classes that implement it to declare all the abstract interface methods. 
B)  can be used in place of an abstract class when there is no default implementation to inherit. 
C)  is declared in a file by itself and is saved in a file with the same name as the interface followed by the .java extension. 
D)  can be instantiated.

Question 10

Polymorphism allows for specifics to be dealt with during:

Accepted Answer

A)  execution. 
B)  compilation. 
C)  programming. 
D)  debugging. 
A)  execution. 
B)  compilation. 
C)  programming. 
D)  debugging.

Question 11

All of the following methods are implicitly final except:

Accepted Answer

A)  a method in an abstract class. 
B)  a private method. 
C)  a method declared in a final class. 
D)  static method. 
A)  a method in an abstract class. 
B)  a private method. 
C)  a method declared in a final class. 
D)  static method.

Question 12

Assigning a subclass reference to a superclass variable is safe ________.

Accepted Answer

A)  because the subclass object has an object of its superclass. 
B)  because the subclass object is an object of its superclass. 
C)  only when the superclass is abstract. 
D)  only when the superclass is concrete. 
A)  because the subclass object has an object of its superclass. 
B)  because the subclass object is an object of its superclass. 
C)  only when the superclass is abstract. 
D)  only when the superclass is concrete.

Question 13

Interfaces can have _______methods.

Accepted Answer

A)  0 
B)  1 
C)  2 
D)  any number of 
A)  0 
B)  1 
C)  2 
D)  any number of

Question 14

Which of the following statements is false?

Accepted Answer

A)  Java allows a class to implement multiple interfaces in addition to extending one class. 
B)  Classes declared with implementation inheritance are tightly coupled. 
C)  Classes declared with interface inheritance are tightly coupled. 
D)  An interface also may extend one or more other interfaces. 
A)  Java allows a class to implement multiple interfaces in addition to extending one class. 
B)  Classes declared with implementation inheritance are tightly coupled. 
C)  Classes declared with interface inheritance are tightly coupled. 
D)  An interface also may extend one or more other interfaces.

Exam 10: Object-Oriented Programming: Polymorphism and Interfaces

Declaring a method final means:

Polymorphism enables you to:

Which of the following could be used to declare abstract method method1 in abstract class Class1 (method1 returns an int and takes no arguments)?

The UML distinguishes an interface from other classes by placing the word "interface" in________ above the interface name.

Consider the abstract superclass below: public abstract class Foo { Private int a; Public int b; Public Foo(int aVal, int bVal) { A = aVal; B = bVal; } Public abstract int calculate(); } Any concrete subclass that extends class Foo:

Which of the following statements is false?

Aclass that implements an interface but does not declare all of the interface's methods must be declared ________.

Every object in Java knows its own class and can access this information through method .

Which of the following does not complete the sentence correctly? An interface _______________.

Polymorphism allows for specifics to be dealt with during:

All of the following methods are implicitly final except:

Assigning a subclass reference to a superclass variable is safe ________.

Interfaces can have _______methods.

Which of the following statements is false?

Introduction to Computers, the Internet and Java

Introduction to Java Applications; Inputoutput and Operators

Introduction to Classes, Objects, Methods and Strings

Control Statements: Assignment, and Operators

Control Statements: Logical Operators

Methods: a Deeper Look

Arrays and Arraylists

Classes and Objects: a Deeper Look

Object-Oriented Programming: Inheritance

Exception Handling: a Deeper Look

Javafx Graphical User Interfaces

Javafx Gui

Strings, Characters and Regular Expressions

Files, Inputoutput Streams, Nio and Xml Serialization

Generic Collections

Lambdas and Streams

Recursion

Searching, Sorting and Big O

Generic Classes and Methods: a Deeper Look

Custom Generic Data Structures

Concurrency

Accessing Databases With Jdbc

Swing Gui Components

Graphics and Java 2d

Networking

Java Persistence Api Jpa

Javaserver Faces Web Apps

Javaserver Faces Web Apps

Swing Gui Components

Filters