Question 1

Which of the following statements about a Java interface is NOT true?

Accepted Answer

A)  A Java interface defines a set of methods that are required. 
B)  A Java interface must contain more than one method. 
C)  A Java interface specifies behavior that a class will implement. 
D)  All methods in a Java interface must be abstract. 
A)  A Java interface defines a set of methods that are required. 
B)  A Java interface must contain more than one method. 
C)  A Java interface specifies behavior that a class will implement. 
D)  All methods in a Java interface must be abstract.

Question 2

How do you specify what the program should do when the user clicks a button?

Accepted Answer

A)  Specify the actions to take in a class that implements the ButtonListener interface. 
B)  Specify the actions to take in a class that implements the ButtonEvent interface . 
C)  Specify the actions to take in a class that implements the ActionListener interface. 
D)  Specify the actions to take in a class that implements the EventListener interface. 
A)  Specify the actions to take in a class that implements the ButtonListener interface. 
B)  Specify the actions to take in a class that implements the ButtonEvent interface . 
C)  Specify the actions to take in a class that implements the ActionListener interface. 
D)  Specify the actions to take in a class that implements the EventListener interface.

Question 3

Which of the following is true regarding a class and interface types?

Accepted Answer

A)  You can convert from a class type to any interface type that is in the same package as the class. 
B)  You can convert from a class type to any interface type that the class implements. 
C)  You can convert from a class type to any interface type that the class defines. 
D)  You cannot convert from a class type to any interface type. 
A)  You can convert from a class type to any interface type that is in the same package as the class. 
B)  You can convert from a class type to any interface type that the class implements. 
C)  You can convert from a class type to any interface type that the class defines. 
D)  You cannot convert from a class type to any interface type.

Question 4

Which of the following statements will compile without error?

Accepted Answer

A)  public interface AccountListener()
{
Void actionPerformed(AccountEvent event);
} 
B)  public interface AccountListener()
{
Void actionPerformed(AccountEvent);
} 
C)  public interface AccountListener
{
Void actionPerformed(AccountEvent event);
} 
D)  public abstract AccountListener
{
Void actionPerformed(AccountEvent event);
} 
A)  public interface AccountListener()
{
Void actionPerformed(AccountEvent event);
} 
B)  public interface AccountListener()
{
Void actionPerformed(AccountEvent);
} 
C)  public interface AccountListener
{
Void actionPerformed(AccountEvent event);
} 
D)  public abstract AccountListener
{
Void actionPerformed(AccountEvent event);
}

Question 5

Consider the following code snippet: public class Inventory implements Measurable
{
) . .
Double getMeasure();
{
Return onHandCount;
}
}
The compiler complains that the getMeasure method has a weaker access level than the Measurable interface. Why?

Accepted Answer

A)  All of the methods in a class have a default access level of package access, while the methods of an interface have a default access level of private. 
B)  All of the methods in a class have a default access level of package access, while the methods of an interface have a default access level of public. 
C)  The variable onHandCount was not declared with public access. 
D)  The getMeasure method was declared as private in the Measurable interface. 
A)  All of the methods in a class have a default access level of package access, while the methods of an interface have a default access level of private. 
B)  All of the methods in a class have a default access level of package access, while the methods of an interface have a default access level of public. 
C)  The variable onHandCount was not declared with public access. 
D)  The getMeasure method was declared as private in the Measurable interface.

Which of the following statements about a Java interface is NOT true?

How do you specify what the program should do when the user clicks a button?

Which of the following is true regarding a class and interface types?

Which of the following statements will compile without error?

Consider the following code snippet: public class Inventory implements Measurable { ) . . Double getMeasure(); { Return onHandCount; } } The compiler complains that the getMeasure method has a weaker access level than the Measurable interface. Why?

Introduction

Using Objects

Implementing Classes

Fundamental Data Types

Decisions

Loops

Arrays and Array Lists

Designing Classes

Inheritance

Inputoutput and Exception Handling

Object-Oriented Design

Recursion

Sorting and Searching

The Java Collections Framework

Basic Data Structures

Tree Structures

Generic Classes

Graphical User Interfaces

Streams and Binary Inputoutput

Multithreading

Internet Networking

Relational Databases

XML

Web Applications

Filters

Exam 10: Interfaces

Which of the following statements about a Java interface is NOT true?

How do you specify what the program should do when the user clicks a button?

Which of the following is true regarding a class and interface types?

Which of the following statements will compile without error?

Consider the following code snippet: public class Inventory implements Measurable { ) . . Double getMeasure(); { Return onHandCount; } } The compiler complains that the getMeasure method has a weaker access level than the Measurable interface. Why?

Introduction

Using Objects

Implementing Classes

Fundamental Data Types

Decisions

Loops

Arrays and Array Lists

Designing Classes

Inheritance

Inputoutput and Exception Handling

Object-Oriented Design

Recursion

Sorting and Searching

The Java Collections Framework

Basic Data Structures

Tree Structures

Generic Classes

Graphical User Interfaces

Streams and Binary Inputoutput

Multithreading

Internet Networking

Relational Databases

XML

Web Applications

Filters