Question 1

In addition to providing a mechanism to convert primitive data into objects, what else do the wrapper classes provide?

Accepted Answer

A)  enumerations 
B)  static constants 
C)  arrays to contain the data 
D)  exceptions 
E)  None of these 
A)  enumerations 
B)  static constants 
C)  arrays to contain the data 
D)  exceptions 
E)  None of these

Question 2

These two ways to set up a String will yield identical results:
String my_string = new String("a bunch of words");
String my_string = "a bunch of words";

Accepted Answer

A) True 
 B)False

Question 3

Rewrite the following five assignment statements into a single statement using prefix and postfix increment and decrement operators as necessary. Assume all variables are int variables.
x = y + 1;
y = y + 1;
z = z - 1;
x = x - z;
x = x + 1;

Accepted Answer

x = (y++ +

Question 4

The advantage(s) of the Random class's pseudorandom number generators, compared to the Math.random method, is(are) that

Accepted Answer

A)  you may create several random number generators 
B)  the generators in Random are more efficient than the one in Math.random 
C)  you can generate random ints, floats, and ints within a range 
D)  you can initialize and reinitialize Random generators 
E)  all except B are true 
A)  you may create several random number generators 
B)  the generators in Random are more efficient than the one in Math.random 
C)  you can generate random ints, floats, and ints within a range 
D)  you can initialize and reinitialize Random generators 
E)  all except B are true

Question 5

Problem Ch 03-1
Assume an interactive Java program which asks the user for his/her first name and last name, and outputs the user's initials.
-Refer to Problem Ch 03-1. For the program to get a name interactively a Scanner object must be instantiated. Write the Java statement to do this.

Accepted Answer

Scanner sc

Question 6

If two variables contain aliases of the same object then

Accepted Answer

A)  the object may be modified using either alias 
B)  the object cannot be modified unless there's a single reference to it 
C)  a third alias is created if/when the object is modified 
D)  the object will become an "orphan" if both variables are set to null 
E)  answers A and D are both correct 
A)  the object may be modified using either alias 
B)  the object cannot be modified unless there's a single reference to it 
C)  a third alias is created if/when the object is modified 
D)  the object will become an "orphan" if both variables are set to null 
E)  answers A and D are both correct

Question 7

In Java a variable may contain

Accepted Answer

A)  a value or a reference 
B)  a package 
C)  a method 
D)  a class 
E)  Any of these 
A)  a value or a reference 
B)  a package 
C)  a method 
D)  a class 
E)  Any of these

Question 8

Assume you write a program that uses the Random class but you fail to include an import statement for java.util.Random or java.util.*. What will happen when you attempt to compile and run your program?

Accepted Answer

A)  The program won't run but it will compile with a warning about missing the class. 
B)  The program won't compile and you'll receive a syntax error about the missing class. 
C)  The program will compile but you'll receive a warning about the missing class. 
D)  The program will encounter a run-time error when it attempts to access any member of the Random class. 
E)  none of these 
A)  The program won't run but it will compile with a warning about missing the class. 
B)  The program won't compile and you'll receive a syntax error about the missing class. 
C)  The program will compile but you'll receive a warning about the missing class. 
D)  The program will encounter a run-time error when it attempts to access any member of the Random class. 
E)  none of these

Question 9

The following statement will display the value 127.
System.out.println("123" + 4);

Accepted Answer

A) True 
 B)False

Question 10

All the methods in the Math class are declared to be static.

Accepted Answer

A) True 
 B)False

Question 11

Which of the following packages includes classes that represent shapes in JavaFX?

Accepted Answer

A)  javafx.scene.shape 
B)  javafx.shape.scene 
C)  javafx.shapes 
D)  javafx.stage.shape 
E)  javafx.stage.scene 
A)  javafx.scene.shape 
B)  javafx.shape.scene 
C)  javafx.shapes 
D)  javafx.stage.shape 
E)  javafx.stage.scene

Question 12

What does the following code fragment do? Circle circle = new Circle(100, 100, 50);
Circle.setFill(Color.GREEN);
Rectangle rectangle = new Rectangle(70, 70, 225, 75);
Rectangle.setStroke(Color.BLUE);
Rectangle.setStrokeWidth(2);
Rectangle.setFill(null);

Accepted Answer

A)  It creates a green circle, centered at coordinates (100, 100). 
B)  It creates a rectangle which overlaps the circle since its upper-left corner is at coordinates (70, 70) and its dimensions are 225 X 75. 
C)  Since the rectangle's fill color is set to null, the circle will be visible through the rectangle. 
D)  The rectangle will have a blue border. 
E)  All of these are true. 
A)  It creates a green circle, centered at coordinates (100, 100). 
B)  It creates a rectangle which overlaps the circle since its upper-left corner is at coordinates (70, 70) and its dimensions are 225 X 75. 
C)  Since the rectangle's fill color is set to null, the circle will be visible through the rectangle. 
D)  The rectangle will have a blue border. 
E)  All of these are true.

Question 13

You may apply the prefix and postfix increment and decrement operators to instances of the Integer class.

Accepted Answer

A) True 
 B)False

Question 14

You may use the String.replace() method to remove characters from a String.

Accepted Answer

A) True 
 B)False

Question 15

Problem Ch 03-1
Assume an interactive Java program which asks the user for his/her first name and last name, and outputs the user's initials.
-Refer to Problem Ch 03-1. Write a method to extract the initial from the first name.

Accepted Answer

firstIniti

Question 16

Consider the condition (x == y). How is this handled if x and y are primitive types? How is this handled if x and y are objects?

Accepted Answer

If x and y are primitive types, then the

Question 17

What is a wrapper class? Why are wrapper classes useful?

Accepted Answer

A wrapper class is a class that allows y

Question 18

In the StringMutation program shown in Listing 3.1, if phrase is initialized to "Einstein", what will Mutation # 3 yield if mutation1 = phrase.concat(".")?

Accepted Answer

A)  Einstein. 
B)  EINSTEIN. 
C)  XINSTXIN. 
D)  einstein. 
E)  xinstxin. 
A)  Einstein. 
B)  EINSTEIN. 
C)  XINSTXIN. 
D)  einstein. 
E)  xinstxin.

Question 19

Which properties are true of String objects?

Accepted Answer

A)  Their lengths never change. 
B)  The shortest String has zero length. 
C)  Individual characters within a String may be changed using the replace method. 
D)  The index of the first character in a String is one. 
E)  Only answers A and B are true. 
A)  Their lengths never change. 
B)  The shortest String has zero length. 
C)  Individual characters within a String may be changed using the replace method. 
D)  The index of the first character in a String is one. 
E)  Only answers A and B are true.

Question 20

What will be displayed by the following command? System.out.println(Math.pow(3, 3-1));

Accepted Answer

A)  9 
B)  8 
C)  6 
D)  4 
E)  27 
A)  9 
B)  8 
C)  6 
D)  4 
E)  27

In addition to providing a mechanism to convert primitive data into objects, what else do the wrapper classes provide?

These two ways to set up a String will yield identical results: String my_string = new String("a bunch of words"); String my_string = "a bunch of words";

Rewrite the following five assignment statements into a single statement using prefix and postfix increment and decrement operators as necessary. Assume all variables are int variables. x = y + 1; y = y + 1; z = z - 1; x = x - z; x = x + 1;

The advantage(s) of the Random class's pseudorandom number generators, compared to the Math.random method, is(are) that

Problem Ch 03-1 Assume an interactive Java program which asks the user for his/her first name and last name, and outputs the user's initials. -Refer to Problem Ch 03-1. For the program to get a name interactively a Scanner object must be instantiated. Write the Java statement to do this.

If two variables contain aliases of the same object then

In Java a variable may contain

Assume you write a program that uses the Random class but you fail to include an import statement for java.util.Random or java.util.*. What will happen when you attempt to compile and run your program?

The following statement will display the value 127. System.out.println("123" + 4);

All the methods in the Math class are declared to be static.

Which of the following packages includes classes that represent shapes in JavaFX?

What does the following code fragment do? Circle circle = new Circle(100, 100, 50); Circle.setFill(Color.GREEN); Rectangle rectangle = new Rectangle(70, 70, 225, 75); Rectangle.setStroke(Color.BLUE); Rectangle.setStrokeWidth(2); Rectangle.setFill(null);

You may apply the prefix and postfix increment and decrement operators to instances of the Integer class.

You may use the String.replace() method to remove characters from a String.

Problem Ch 03-1 Assume an interactive Java program which asks the user for his/her first name and last name, and outputs the user's initials. -Refer to Problem Ch 03-1. Write a method to extract the initial from the first name.

Consider the condition (x == y). How is this handled if x and y are primitive types? How is this handled if x and y are objects?

What is a wrapper class? Why are wrapper classes useful?

In the StringMutation program shown in Listing 3.1, if phrase is initialized to "Einstein", what will Mutation # 3 yield if mutation1 = phrase.concat(".")?

Which properties are true of String objects?

What will be displayed by the following command? System.out.println(Math.pow(3, 3-1));

Introduction

Data and Expressions

Writing Classes

Conditionals and Loops

More Conditionals and Loops

Object-Oriented Design

Arrays

Inheritance

Polymorphism

Exceptions

Recursion

Collections

Filters

Exam 3: Using Classes and Objects

In addition to providing a mechanism to convert primitive data into objects, what else do the wrapper classes provide?

These two ways to set up a String will yield identical results: String my_string = new String("a bunch of words"); String my_string = "a bunch of words";

Rewrite the following five assignment statements into a single statement using prefix and postfix increment and decrement operators as necessary. Assume all variables are int variables. x = y + 1; y = y + 1; z = z - 1; x = x - z; x = x + 1;

The advantage(s) of the Random class's pseudorandom number generators, compared to the Math.random method, is(are) that

Problem Ch 03-1 Assume an interactive Java program which asks the user for his/her first name and last name, and outputs the user's initials. -Refer to Problem Ch 03-1. For the program to get a name interactively a Scanner object must be instantiated. Write the Java statement to do this.

If two variables contain aliases of the same object then

In Java a variable may contain

Assume you write a program that uses the Random class but you fail to include an import statement for java.util.Random or java.util.*. What will happen when you attempt to compile and run your program?

The following statement will display the value 127. System.out.println("123" + 4);

All the methods in the Math class are declared to be static.

Which of the following packages includes classes that represent shapes in JavaFX?

What does the following code fragment do? Circle circle = new Circle(100, 100, 50); Circle.setFill(Color.GREEN); Rectangle rectangle = new Rectangle(70, 70, 225, 75); Rectangle.setStroke(Color.BLUE); Rectangle.setStrokeWidth(2); Rectangle.setFill(null);

You may apply the prefix and postfix increment and decrement operators to instances of the Integer class.

You may use the String.replace() method to remove characters from a String.

Problem Ch 03-1 Assume an interactive Java program which asks the user for his/her first name and last name, and outputs the user's initials. -Refer to Problem Ch 03-1. Write a method to extract the initial from the first name.

Consider the condition (x == y). How is this handled if x and y are primitive types? How is this handled if x and y are objects?

What is a wrapper class? Why are wrapper classes useful?

In the StringMutation program shown in Listing 3.1, if phrase is initialized to "Einstein", what will Mutation # 3 yield if mutation1 = phrase.concat(".")?

Which properties are true of String objects?

What will be displayed by the following command? System.out.println(Math.pow(3, 3-1));

Introduction

Data and Expressions

Writing Classes

Conditionals and Loops

More Conditionals and Loops

Object-Oriented Design

Arrays

Inheritance

Polymorphism

Exceptions

Recursion

Collections

Filters