Question 1

A mutator method of a class changes the values of the data members of the class.

Accepted Answer

A) True 
 B)False

Question 2

public class Secret
{
Private int x;
Private static int y;
Public static int count;
Public int z;
Public Secret()
{
X = 0;
Z = 1;
} public Secret(int a)
{
X = a;
} public Secret(int a, int b)
{
X = a;
Y = b;
} public String toString()
{
Return ("x = " + x + ", y = " + y + ",
Count = " + count);
} public static void incrementY()
{
Y++;
}
}What might the heading of the copy constructor for the class in the accompanying figure look like?

Accepted Answer

A)  public Secret(Secret s) 
B)  private copySecret() 
C)  Secret copySecret = new Secret() 
D)  public copySecret(int a, int b) 
A)  public Secret(Secret s) 
B)  private copySecret() 
C)  Secret copySecret = new Secret() 
D)  public copySecret(int a, int b)

Question 3

In shallow copying, each reference variable refers to its own object.

Accepted Answer

A) True 
 B)False

Question 4

Consider the following class definition.public class Rectangle
{
Private double length;
Private double width; public Rectangle()
{
Length = 0;
Width = 0;
} public Rectangle(double l, double w)
{
Length = l;
Width = w;
} public void set(double l, double w)
{
Length = l;
Width = w;
} public void print()
{
System.out.println(length + " " + width);
} public double area()
{
Return length * width;
} public double perimeter()
{
Return 2 * length + 2 * width;
}
}Which of the following statements correctly instantiates the Rectangle object myRectangle?
(i) myRectangle = new Rectangle(12.5, 6);
(ii) Rectangle myRectangle = new Rectangle(12.5, 6);
(iii) class Rectangle myRectangle = new Rectangle(12.5, 6);

Accepted Answer

A)  Only (i) 
B)  Only (ii) 
C)  Only (iii) 
D)  Both (ii) and (iii) 
A)  Only (i) 
B)  Only (ii) 
C)  Only (iii) 
D)  Both (ii) and (iii)

Question 5

Every object has access to a reference to itself.

Accepted Answer

A) True 
 B)False

Question 6

Consider the following class definition.public class Cylinder
{
Private double baseRadius;
Private double height; public Cylinder ()
{
BaseRadius = 0;
Height = 0;
} public Cylinder (double l, double h)
{
BaseRadius = l;
Height = h;
} public void set(double r, double h)
{
BaseRadius = r;
Height = h;
} public String toString()
{
Return (baseRadius + " " + height);
} public double SurfaceArea()
{
Return 2 * 3.14 * baseRadius * height;
} public double volume()
{
Return 3.14 * baseRadius * baseRadius * height;
}
}Suppose that you have the following declaration. Cylinder cyl = new Cylinder(1.5, 10);Which of the following sets of statements are valid in Java?
(i)
Cyl.surfaceArea();
Cyl.volume();
Cyl.print();
(ii)
Print(cyl.surfaceArea);
Print(cyl.volume());

Accepted Answer

A)  Only (i) 
B)  Only (ii) 
C)  Both (i) and (ii) 
D)  None of these 
A)  Only (i) 
B)  Only (ii) 
C)  Both (i) and (ii) 
D)  None of these

Question 7

A constructor has no type and is therefore a void method.

Accepted Answer

A) True 
 B)False

Question 8

MysteryClass
-first: int
-second: double;
+MysteryClass()
+MysteryClass(int)
+MysteryClass(double);
+MysteryClass(int, double)
+setData(int, double): void
+getFirst(): int
+getSecond(): double
+doubleFirst(): int
+squareSecond(): double
+print(): void
+equals(MysteryClass): boolean
+makeCopy(MysteryClass): void
+getCopy():MysteryClass
According to the UML class diagram in the accompanying figure, which method is public and doesn't return anything?

Accepted Answer

A)  getCopy() 
B)  print() 
C)  equals(MysteryClass) 
D)  doubleFirst() 
A)  getCopy() 
B)  print() 
C)  equals(MysteryClass) 
D)  doubleFirst()

Question 9

Modifiers are used to alter the behavior of the class.

Accepted Answer

A) True 
 B)False

Question 10

public class Secret
{
Private int x;
Private static int y;
Public static int count;
Public int z;
Public Secret()
{
X = 0;
Z = 1;
} public Secret(int a)
{
X = a;
} public Secret(int a, int b)
{
X = a;
Y = b;
} public String toString()
{
Return ("x = " + x + ", y = " + y + ",
Count = " + count);
} public static void incrementY()
{
Y++;
}
}Based on the class in the accompanying figure, which of the following statements is illegal?

Accepted Answer

A)  Secret.incrementY(); 
B)  Secret.count++; 
C)  Secret.z++; 
D)  Secret secret = new Secret(4); 
A)  Secret.incrementY(); 
B)  Secret.count++; 
C)  Secret.z++; 
D)  Secret secret = new Secret(4);

Question 11

The method finalize automatically executes when the class object goes out of scope.

Accepted Answer

A) True 
 B)False

Question 12

In Java, the reference this is used to refer to only the methods, not the instance variables of a class.

Accepted Answer

A) True 
 B)False

Question 13

ADTs illustrate the principle of ____.

Accepted Answer

A)  information hiding 
B)  privacy 
C)  encapsulation 
D)  overloading 
A)  information hiding 
B)  privacy 
C)  encapsulation 
D)  overloading

Question 14

What is the default definition of the method toString?

Accepted Answer

A)  There is no default definition; you must define the method yourself. 
B)  It creates a string that is the name of the object's class, followed by the hash code of the object. 
C)  It creates a string that is the name of the program. 
D)  It creates a string that is the name of the package, followed by the name of the class, followed by the hash of the object. 
A)  There is no default definition; you must define the method yourself. 
B)  It creates a string that is the name of the object's class, followed by the hash code of the object. 
C)  It creates a string that is the name of the program. 
D)  It creates a string that is the name of the package, followed by the name of the class, followed by the hash of the object.

Question 15

The built-in operation that is valid for classes is the dot operator.

Accepted Answer

A) True 
 B)False

Question 16

When does the method finalize execute?

Accepted Answer

A)  When the class object is created 
B)  At the start of every program 
C)  At the end of every program 
D)  When the class object goes out of scope 
A)  When the class object is created 
B)  At the start of every program 
C)  At the end of every program 
D)  When the class object goes out of scope

Question 17

An accessor method of a class first accesses the values of the data members of the class and then changes the values of the data members.

Accepted Answer

A) True 
 B)False

Question 18

public class Secret
{
Private int x;
Private static int y;
Public static int count;
Public int z;
Public Secret()
{
X = 0;
Z = 1;
} public Secret(int a)
{
X = a;
} public Secret(int a, int b)
{
X = a;
Y = b;
} public String toString()
{
Return ("x = " + x + ", y = " + y + ",
Count = " + count);
} public static void incrementY()
{
Y++;
}
}What does the default constructor do in the class definition in the accompanying figure?

Accepted Answer

A)  Sets the value of x to 0 
B)  Sets the value of z to 1 
C)  Sets the value of x to 0 and the value of z to 1 
D)  There is no default constructor. 
A)  Sets the value of x to 0 
B)  Sets the value of z to 1 
C)  Sets the value of x to 0 and the value of z to 1 
D)  There is no default constructor.

Question 19

In deep copying, each reference variable refers to its own object.

Accepted Answer

A) True 
 B)False

Question 20

When no object of the class type is instantiated, static data members of the class fail to exist.

Accepted Answer

A) True 
 B)False

A mutator method of a class changes the values of the data members of the class.

In shallow copying, each reference variable refers to its own object.

Every object has access to a reference to itself.

A constructor has no type and is therefore a void method.

Modifiers are used to alter the behavior of the class.

The method finalize automatically executes when the class object goes out of scope.

In Java, the reference this is used to refer to only the methods, not the instance variables of a class.

ADTs illustrate the principle of ____.

What is the default definition of the method toString?

The built-in operation that is valid for classes is the dot operator.

When does the method finalize execute?

An accessor method of a class first accesses the values of the data members of the class and then changes the values of the data members.

In deep copying, each reference variable refers to its own object.

When no object of the class type is instantiated, static data members of the class fail to exist.

An Overview of Computers and Programming Languages

Basic Elements of Java

Introduction to Objects and Input/output

Control Structures I: Selection

Control Structures II: Repetition

Graphical User Interface GUI and Object-Oriented Design OOD

User-Defined Methods

Arrays

Inheritance and Polymorphism

Handling Exceptions and Events

Advanced Guis and Graphics

Recursion

Applications of Arrays Searching and Sorting and Strings

Filters

Exam 8: User-Defined Classes

A mutator method of a class changes the values of the data members of the class.

In shallow copying, each reference variable refers to its own object.

Every object has access to a reference to itself.

A constructor has no type and is therefore a void method.

Modifiers are used to alter the behavior of the class.

The method finalize automatically executes when the class object goes out of scope.

In Java, the reference this is used to refer to only the methods, not the instance variables of a class.

ADTs illustrate the principle of ____.

What is the default definition of the method toString?

The built-in operation that is valid for classes is the dot operator.

When does the method finalize execute?

An accessor method of a class first accesses the values of the data members of the class and then changes the values of the data members.

In deep copying, each reference variable refers to its own object.

When no object of the class type is instantiated, static data members of the class fail to exist.

An Overview of Computers and Programming Languages

Basic Elements of Java

Introduction to Objects and Input/output

Control Structures I: Selection

Control Structures II: Repetition

Graphical User Interface GUI and Object-Oriented Design OOD

User-Defined Methods

Arrays

Inheritance and Polymorphism

Handling Exceptions and Events

Advanced Guis and Graphics

Recursion

Applications of Arrays Searching and Sorting and Strings

Filters