Deck 2: Using Objects

Question 1

The camel case naming convention uses _________ at intervals in the middle of the variable name.

A)uppercase letters
B)digits
C)dollar signs
D)the underscore character

Answer 1

uppercase letters

Question 2

By convention among Java programmers, class names begin with a(n) _____________.

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

Answer 2

uppercase letter

Question 3

What term is used to refer to text in a program that is an explanation for human readers of the code?

A)methods
B)comments
C)constants
D)[* and *]

Answer 3

comments

Question 4

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 5

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

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

Question 6

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

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

Question 7

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

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

Question 8

You can invoke the println and print methods on which object?

A)the HelloWorld object
B)the String class
C)any PrintStream object
D)any object in Java

Question 9

In Java, a comment on a line begins with which characters?

A)''
B)//
C)()
D)" "

Question 10

A method is a sequence of ___ that accesses the data of an object.

A)data
B)objects
C)instructions
D)streams

Question 11

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

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

Question 12

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 13

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;

Question 14

In Java, a(n) _________ specifies the kind of values that can be stored in a variable.

A)literal
B)class
C)operator
D)type

Question 15

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 16

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 17

The "building blocks" that Java programmers use to write computer programs are called _______.

A)windows
B)objects
C)internal data
D)entities

Question 18

In Java, objects within the same class share common _______.

A)behavior
B)data
C)instructions
D)comments

Question 19

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 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

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 22

Which statement stores an integer value in a variable?

A)count = 5;
B)count = 5.0;
C)count == 5;
D)count != 5;

Question 23

What is the term used to specify the collection of things you can do with objects that belong to a class?

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

Question 24

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 25

What is the name of the = operator in Java?

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

Question 26

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 27

The type of an object is given by its ______ ?

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

Question 28

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

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

Question 29

The Java compiler ignores any text between ____.

A)(* and *)
B)/* and */
C){* and *}
D)// and //

Question 30

The value calculated by a method is called its _____ value.

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

Question 31

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 32

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

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

Question 33

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 34

"System.out" is an example of which class?

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

Question 35

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

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

Question 36

Assuming 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 = 6.0;

Question 37

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

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

Question 38

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 39

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 40

Which statement about methods is true?

A)A method must return a value
B)The return value of a method must be stored in a variable
C)Some methods carry out an action; others return a value
D)All methods require multiple arguments

Question 41

What does API stand for?

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

Question 42

A(n) _____________ is a collection of classes with a related purpose.

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

Question 43

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 44

Which operator constructs object instances?

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

Question 45

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 46

Which is not a method of the String class?

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

Question 47

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

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

Question 48

Which statement calls a constructor with no construction arguments?

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

Question 49

Which term describes a method of an object that modifies that object's internal data?

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

Question 50

Which statement declares a variable that references a Circle of radius 3, assuming the construction parameter is the radius value?

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

Question 51

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 52

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 53

Which package is automatically imported in any Java program?

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

Question 54

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

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

Question 55

Which of the following method calls illustrate using the return value of a method as an argument?

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

Question 56

Which of the following statements about methods is correct?

A)A method can have only one argument.
B)The return value of a method can be used as an argument to another method.
C)Every method must have a return value.
D)A method can have multiple arguments.

Question 57

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 58

What terminology describes a method that returns information about an object and does not change the object's internal data?

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

Question 59

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 60

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

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

Question 61

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 62

What is the output of the following code:

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

Question 63

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

A)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 64

Which class is part of the java.lang package?

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

Question 65

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

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

Question 66

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 67

What is the output of the following code:

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

Question 68

What do object variables store?

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

Question 69

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

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

Question 70

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

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

Question 71

What is the output of the following code:

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

Question 72

What is the purpose of a test program?

A)The test program confirms that the Java compiler is correct.
B)The test program verifies that methods have been implemented correctly.
C)The test program checks the syntax of each object's methods.
D)The test program enforces that the types between arguments match correctly.

Question 73

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 74

What is the output of the following code:

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

Question 75

Drawing instructions should be placed inside the ____ method, which is called whenever the component needs to be repainted.

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

Question 76

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 77

The setVisible method of the JFrame class returns what kind of argument?

A)The setVisible method does not return a result.
B)The setVisible method returns an integer value.
C)The setVisible method returns a String object.
D)The setVisible method returns a JFrame object.

Question 78

Assume the class Circle has an accessor called getRadius and a mutator called setRadius.What is the output of the following code?

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

Question 79

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

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

Question 80

Based on the following code, which of the following statements sets the frame to a width of 400 and a height of 200:

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);