Deck 2: Using Objects

Question 1

A set of values and the operations that can be carried out with those values are called _______.

A) literals
B) numbers
C) values
D) types

Answer 1

D

Question 2

What is the name of the = operator in Java?

A) inequality
B) assignment
C) identity
D) equality

Answer 2

B

Question 3

Which of the following declares a variable that will store a measurement with fractional parts?

A) int measure;
B) double measure;
C) String measure;
D) integer measure;

Answer 3

B

Question 4

Which of the following declares a variable that will store a count with an integer value?

A) integer count;
B) double count;
C) String count;
D) int count;

Question 5

What is the purpose of the assignment operator?

A) to check for inequality
B) to check for identity
C) to check for equality
D) to change the value of a variable

Question 6

By convention, classes begin with a(n) _____________.

A) lowercase letter
B) dollar sign
C) digit
D) uppercase letter

Question 7

By convention, variables begin with a(n) _____________.

A) uppercase letter
B) digit
C) lowercase letter
D) dollar sign

Question 8

What is the name of the type that denotes whole numbers?

A) double
B) int
C) whole
D) integer

Question 9

Which statement stores an integer value in a variable?

A) count = 5;
B) String count = 5;
C) int count;
D) integer count = 5;

Question 10

Which statement declares a variable that will store an integer value?

A) integer count;
B) int count;
C) count = 5;
D) String count = 5;

Question 11

Which term is used to describe the name of a variable, method, or class?

A) type
B) literal
C) identifier
D) label

Question 12

Which statement declares and stores an integer value in a variable?

A) count = 5;
B) int count = 5;
C) integer count = 5;
D) String count = 5;

Question 13

What is the name of the type that denotes a string of characters?

A) Characters
B) char
C) charString
D) String

Question 14

Which of the following values does not have a primitive type?

A) 12.50
B) "Hello"
C) 6
D) 1E4

Question 15

Which of the following is the best choice for a variable identifier that will store a name?

A) name
B) Name
C) n
D) nm

Question 16

Which is a valid number literal?

A) 1x10^4
B) 1E4
C) 3 1/2
D) 10,000

Question 17

Which statement about identifiers is correct?

A) Identifiers are not case sensitive.
B) Spaces are permitted inside identifiers.
C) Identifiers can use symbols such as ? or %.
D) Identifiers can be made up of letters, digits, and the underscore (_) character.

Question 18

Which of the following declares a variable that will store a welcome message?

A) String welcome;
B) double welcome;
C) Char welcome;
D) int welcome;

Question 19

What is the name of the type that denotes floating-point numbers that can have fractional parts?

A) double
B) floatingPoint
C) int
D) integer

Question 20

What is a storage location in the computer's memory called that has a type, name, and contents?

A) identifier
B) literal
C) label
D) variable

Question 21

Assume that the variable count has been declared as type int. Which statement adds 10 to count?

A) count = 10;
B) count == count + 10;
C) count = count + 10;
D) count + 10;

Question 22

Which of the following statements about objects is correct?

A) An object defines the methods for a class.
B) Every object belongs to a class.
C) An object is a sequence of instructions.
D) All entities, even numbers, are objects.

Question 23

Which of the following statements about methods is correct?

A) A method is a sequence of instructions that could access the data of an object
B) A method name is unique across the entire program.
C) A method can be called on any object in any class.
D) Methods are stored in variables.

Question 24

Input to a method enclosed in parentheses after the method name is known as ______________.

A) implicit parameters
B) interfaces
C) explicit parameters
D) return values

Question 25

Which of the following statements about classes is correct?

A) By convention, class names begin with a lowercase letter.
B) A class declares the methods that you can apply to its objects.
C) All entities, even primitive numbers, are classes.
D) A class is a sequence of instructions that accesses the data of an object.

Question 26

Assume that the variable count has been declared as type int, which statement changes the value of count?

A) count = 6;
B) count == 6;
C) integer count = 6;
D) count := 6;

Question 27

What is the type of an object?

A) variable
B) method
C) reference
D) class

Question 28

If greeting is a String object, which method call is incorrect?

A) greeting.length()
B) greeting.toLowerCase()
C) greeting.toUpperCase()
D) greeting.println()

Question 29

Which of the following statements about methods is correct?

A) A method can have only one explicit parameter.
B) The return value of a method can be used as a parameter.
C) Every method must have a return value.
D) A method can have multiple implicit parameters.

Question 30

Which is not a method of the String class?

A) length
B) toUpperCase
C) toLowerCase
D) println

Question 31

Which method call represents the invocation of a method that does not have explicit parameters?

A) greeting.replace("Hello", "Welcome");
B) greeting.length
C) greeting.length()
D) System.out.println(greeting);

Question 32

The object on which the method call is invoked provides input to the method, and is called a(n) _________________.

A) interface
B) procedure
C) implicit parameter
D) explicit parameter

Question 33

What is an object?

A) A sequence of instructions.
B) Any value stored in a variable.
C) An entity in your program that is manipulated by calling methods.
D) Any input to a method.

Question 34

The output of a method is called its __________ value.

A) implicit
B) explicit
C) parameter
D) return

Question 35

"System.out" is an instance of (example of?) which class?

A) String
B) Println
C) System
D) PrintStream

Question 36

A method name is ____________________ if a class has more than one method with that name (but different parameter types).

A) overridden
B) overimplemented
C) overwhelmed
D) overloaded

Question 37

The input to a method is called a(n) _______________.

A) overloaded
B) parameter
C) interface
D) procedure

Question 38

Which of the following code fragments will cause an error?

A) String greeting = "Hello, Dave!";
B) String greeting = "Hello, World!"; int n = greeting.length();
C) int luckyNumber; System.out.println(luckyNumber);
D) PrintStream printer = System.out;

Question 39

What is the term used to specify the remote control for a class, indicating what you can do with the objects that belong to the class?

A) private interface
B) public interface
C) private implementation
D) hidden implementation

Question 40

Which of the following method calls illustrates the return value of a method as a parameter?

A) greeting.length();
B) greeting.println("Hello");
C) System.out.println(length.greeting());
D) System.out.println(greeting.length());

Question 41

Which statement calls a constructor with no construction parameters?

A) Circle c = new Circle();
B) A call to a constructor must have construction parameters.
C) Circle c = new Circle;
D) Circle c = Circle()

Question 42

To use a class in another package you need to ________ it.

A) export
B) overload
C) rewrite
D) import

Question 43

Which of the following represents a method call to a method with a void return type?

A) greeting.isEmpty()
B) System.out.println()
C) greeting.replace("Hello","World")
D) greeting.length()

Question 44

What terminology describes a method that modifies the internal data of its implicit parameter?

A) public
B) void
C) mutator
D) accessor

Question 45

Which of the following constructs a Circle of radius 3, assuming the construction parameter is the radius value?

A) Circle(3).new
B) new Circle(3)
C) new.Circle(3)
D) Circle(3)

Question 46

A _____________ is a collection of classes with a related purpose.

A) package
B) import
C) method
D) collection

Question 47

What does API stand for?

A) Applet Programming Interface
B) Application Programmer Interaction
C) Application Programming Instance
D) Application Programming Interface

Question 48

What is the declared return type for a method that does not have a return value?

A) String
B) There is no declared return type when a method does not return a value.
C) void
D) A method must return a value.

Question 49

Which method checks whether a point lies within the rectangle?

A) add
B) getBounds
C) translate
D) contains

Question 50

If greeting refers to a String object, which of the following is a syntactically correct Java statement?

A) System.out.println(length().greeting);
B) System.out.println(greeting());
C) System.out.println(greeting.length());
D) greeting.println("Hello");

Question 51

Which of the following is a mutator method for the Rectangle class?

A) getHeight
B) translate
C) getWidth
D) isEmpty

Question 52

Which statement declares a variable that references a Circle of radius 3?

A) Circle c = Circle(3)
B) Circle c = new Circle(3);
C) Circle c.new.Circle(3);
D) c.Circle(3);

Question 53

Which package is automatically imported in any Java program?

A) java.system
B) java.lang
C) java.language
D) java.util

Question 54

Which method would you use to obtain the string "1234567890" from the string "123-456-7890"?

A) isEmpty
B) replace
C) trim
D) length

Question 55

Which of the following represents a method declaration with a void return type?

A) public void setValue(int value) { ... }
B) public void int getValue() { ... }
C) void public setValue(int value) { ... }
D) void int getValue() { ... }

Question 56

What terminology describes a method that returns information about its implicit parameter and does not change the parameter's internal data?

A) mutator
B) accessor
C) void
D) public

Question 57

Which of the following statements about test programs is true?

A) Test programs verify that methods have been implemented correctly.
B) A tester class does not contain the main method.
C) You do not have to display the expected results.
D) Writing test programs is not an important skill.

Question 58

Which import statement allows for the use of the Rectangle class?

A) import java.geom.Rectangle2D;
B) import java.geom.Rectangle;
C) import java.geom.RectangularShape;
D) import java.awt.Rectangle;

Question 59

Which operator constructs object instances?

A) new
B) instanceof
C) void
D) construct

Question 60

Which class is part of the java.lang package?

A) Rectangle
B) PrintStream
C) String
D) Circle

Question 61

Assuming the following Java statement:
Int num = 10;
What does the variable num store?

A) A reference to the memory location where the value 10 is stored.
B) A reference to the int primitive type.
C) An object representing the number 10.
D) The numeric value 10.

Question 62

What is the output of the following code:
Int num1 = 6;
Int num2 = num1;
Num2 = num2 + 10;
System.out.println(num1);

A) 6
B) 10
C) 4
D) 16

Question 63

What is the output of the following code: Circle c1 = new Circle(3);
Circle c2 = new Circle(3);
C1)setRadius(4);
System.out.println(c2.getRadius());

A) 3
B) 8
C) 6
D) 4

Question 64

Assuming the following Java statement: Circle c1 = new Circle(3);
What does the variable c1 store?

A) The constructed object itself.
B) A reference to the Circle class.
C) A reference to the memory location of the constructed object.
D) The numeric value 3.

Question 65

What do object variables store?

A) objects
B) classes
C) references
D) numbers

Question 66

Place drawing instructions inside the __________ method, which is called whenever the component needs to be repainted.

A) paintComponent
B) draw
C) paint
D) drawComponent

Question 67

Based on the following code, which of the following statements sets the frame to a width of 400 and a height of 200: final int FRAME_WIDTH = 400;
Final int FRAME_HEIGHT = 200;
JFrame frame = new JFrame();

A) frame.size = (FRAME_WIDTH, FRAME_HEIGHT);
B) frame.addSize(FRAME_WIDTH, FRAME_HEIGHT);
C) frame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
D) frame.setSize(FRAME_HEIGHT, FRAME_WIDTH);

Question 68

What is the output of the following code:
Int num1 = 6;
Int num2 = 10;
Num1 = num1 + num2;
Num2 = num1 + num2;
System.out.println(num1 + ", " + num2);

A) 6, 10
B) 16, 16
C) 16, 22
D) 16, 26

Question 69

Complete the following statement, which constructs an ellipse. Ellipse2D.Double ellipse =
New ____________________ (x, y, width, height);

A) Double.Ellipse2D
B) Ellipse2D.Double
C) Ellipse2D
D) Double

Question 70

Based on the following statement, which of the following statements sets the title of the frame: JFrame frame = new JFrame();

A) frame.title = "An Empty Frame";
B) frame.setTitle(JFrame.EMPTY);
C) frame.addTitle("An Empty Frame");
D) frame.setTitle("An Empty Frame");

Question 71

Which of the following terms denotes the memory location of an object?

A) implicit parameter
B) mutator method
C) encapsulation
D) object reference

Question 72

Complete this code fragment to ensure that the frame is shown: JFrame frame = new JFrame();

A) frame.setVisible(true);
B) frame.visible = true;
C) JFrame.setVisible();
D) frame.setVisible();

Question 73

In the code below, write a statement that sets the graphic to green. public class ItalianFlagComponent extends JComponent
{
Public void paintComponent(Graphics

A) g2.setColor(GREEN);
B) g2.SetColor(0, 255, 0);
C) g2.setColor(Color.GREEN);
D) g2.setColor("GREEN");
G) {
Graphics2D g2 = (Graphics2D) g;
Rectangle.Double leftRectangle = new Rectangle.Double(100, 100, 30, 60);
) . .
____
) . .
}
}

Question 74

What is the output of the following code: Circle c1 = new Circle(3);
Circle c2 = c1;
C1)setRadius(4);
System.out.println(c2.getRadius());

A) 4
B) 3
C) 6
D) 8

Question 75

What is the output of the following code:
Int num1 = 6;
Int num2 = 10;
num1 = num2;
num2 = num1;
System.out.println(num1 + ", " + num2);

A) 6, 10
B) 10, 6
C) 6, 6
D) 10, 10

Question 76

What is the nickname for the graphical user interface library in Java?

A) Applet
B) GUI
C) JComponent
D) Swing