Question 1

Encapsulation is supported by ___________
  Methods 
  Objects 
  None of the above 
  Classes

Accepted Answer

Classes

Question 2

[T/F] An interface is typically used in place of an abstract class when there is no default implementation to inherit.

Accepted Answer

True

Question 3

What is a method's signature?
A.) a method is the name of the method the type of its return value. 
B.)a method is the name of the method, its parameter list, and its return type.

Accepted Answer

The signature of a method is the name of the method, its parameter list, and its return type.

Question 4

Which among the following is the language which supports classes but not polymorphism?
  C++ 
  Java 
  SmallTalk 
  Ada

Accepted Answer

Ada

Question 5

Here is a method definition: int compute( a int, y double ){ . . . .} Which of the following has a different signature?
  int compute( a int, y int ){ . . . .} 
  int compute( sum int, value double ){ . . . .}

Accepted Answer

int compute( a int, y double ) { ... }

Question 6

If the processor represents all the functioning of phone, display shows the display only, and the phone is represented as a whole. Which among the following have highest level of abstraction?
  Camera 
  Motherboard 
  Phone 
  Display

Accepted Answer

Phone

Question 7

Which of the following classes fail to compile? class X { } abstract class Y { } abstract class Z { abstract void method(); }
  All classes compile 
  X, Y 
  Y 
  Y, Z 
  X, Y, Z

Accepted Answer

All classes compile

Question 8

Using higher degree of abstraction __________
  May get unsafe 
  Can increase vulnerability 
  Can be safer 
  May reduce readability

Accepted Answer

Can be safer

Question 9

Which among the following can be viewed as combination of abstraction of data and code.
  Interfaces 
  Inheritance 
  Object 
  Class

Accepted Answer

Object

Question 10

What is an exception?
  Problem arising during compile time 
  Problem in syntax 
  Problem arising during runtime 
  Problem in IDE

Accepted Answer

Problem arising during runtime

Question 11

Which symbol should be used to separate the type of exception handler classes in a single catch block?
  , 
  ? 
  – 
  |

Accepted Answer

|

Question 12

The built-in base class in Java, which is used to handle all exceptions is
  Raise 
  Throwable 
  Error 
  Exception

Accepted Answer

Throwable

Question 13

[T / F] Private getter() and setter() methods should not use assertions to verify arguments

Accepted Answer

True

Question 14

[T / F] The programmer can choose to execute a return statement or to throw an exception if an assertion fails.

Accepted Answer

True

Question 15

[T / F] The major drawback to polymorphically designed programs is that they do not take into account the future addition or deletion of classes

Accepted Answer

False

Question 16

[T / F] Examine the following code: String str = "Hot Java"; boolean switch = str instanceof String; What value is placed in switch?

Accepted Answer

True

Question 17

The ability to define more than one function with the same name is called?
  Encapsulation 
  Inheritance 
  Abstraction 
  Polymorphism

Accepted Answer

Polymorphism

Question 18

[T / F] An abstract class cannot have instance data and non-abstract methods.

Accepted Answer

False

Question 19

[T / F] If a subclass reference is assigned to a superclass variable, the variable must be cast back to the subclass before any subclass methods can be called with it.

Accepted Answer

True

Question 20

[T / F] Higher the level of abstraction, higher are the details.

Accepted Answer

False

Question 21

In order for the following code to be correct, what must be the type of the reference variable card?
_________ card;
card = new Valentine( "Joe", 14 ) ;
card.greeting();
card = new Holiday( "Bob" ) ;
card.greeting();

Accepted Answer

Card

Question 22

Abstraction can apply to ____________
  Only control 
  Classes 
  Only data 
  Control and data

Accepted Answer

Control and data

Question 23

What is an abstract class?
  An abstract class is any parent class with more than one child class. 
  An abstract class is class which cannot be instantiated.

Accepted Answer

An abstract class is class which cannot be instantiated.

Question 24

How many catch blocks can a single try block can have?
  Maximum 127 
  Only 2 
  Only 1 
  As many as required

Accepted Answer

As many as required

Question 25

Which class is used to handle the input and output exceptions?
  IOExceptions 
  ExceptionsIO 
  InputOutputExceptions 
  InputOutput

Accepted Answer

IOExceptions

Question 26

MethodX might encounter an IOException or an AWTException, but handles neither. How should the header for methodX be written?

Accepted Answer

public void methodX() throws IOException, AWTException {
    // Method implementation
}

Question 27

[T / F] It is not required for the caller method to catch or re-throw the checked exception.

Accepted Answer

False

Question 28

[T / F] Assertion checking is typically enabled when a program is deployed.

Accepted Answer

False

Question 29

[T / F] It is never appropriate to write code to handle failure of an assert statement.

Accepted Answer

False

Question 30

[T / F] It is never appropriate to write code to handle failure of an assert statement.

Accepted Answer

True

Question 31

[T / F] Assertion checking is typically enabled during program development and testing.

Accepted Answer

True

Question 32

[T / F]  Assertion checking can be selectively enabled or disabled on both a per-package basis and a per-class basis.

Accepted Answer

True

Question 33

[T / F] Assertion checking can be selectively enabled or disabled on a per-package basis, but not on a per-class basis.

Accepted Answer

False

Question 34

[T / F] An abstract class declares a common interface for the various members of a class hierarchy. All classes in the hierarchy can use this same set of methods through polymorphism.

Accepted Answer

True

Question 35

Here is a method definition: int compute( a int, y double ){ . . . .} Which of the following has a different signature?
  int compute( a int, y int ){ . . . .} 
  int compute( sum int, value double ){ . . . .}

Accepted Answer

int compute( a int, y int ){ . . . .}

Question 36

Which among the following can't be used for polymorphism?
  Member functions overloading 
  Static member functions 
  Predefined operator overloading 
  Constructor overloading

Accepted Answer

Static member functions

Question 37

What must be true if a child of an abstract parent class does not override all of the parent's abstract methods?
  The parent class is in error. 
  This is always an error. 
  The child class itself must be declared to be abstract.

Accepted Answer

The child class itself must be declared to be abstract.

Question 38

Can an abstract class define both abstract methods and non-abstract methods?
  No--it must have all abstract methods. 
  No--it must have all one or the other. 
  Yes--the child classes inherit both.

Accepted Answer

Yes--the child classes inherit both.

Question 39

Which of the following classes fail to compile? class X { } abstract class Y { } abstract class Z { abstract void method(); }
  a.)X, Y, Z 
  b.)Y 
  c.)All classes compile 
  d.)Y, Z 
  e.)X, Y

Accepted Answer

c.)All classes compile

Question 40

[T / F] if a class defines an abstract method the class itself must be abstract.

Accepted Answer

True

Question 41

What determines what method is run in the following: Card crd = new BirthDay("Lucinda", 42); crd.greeting(); The type of the object or the type of the reference variable?
  The type of the object. 
  The type of the reference variable.

Accepted Answer

The type of the object.

Question 42

The built-in base class in Java, which is used to handle all exceptions is
  Exception 
  Raise 
  Throwable 
  Error

Accepted Answer

Throwable

Question 43

What is an exception?
  Problem arising during runtime 
  Problem arising during compile time 
  Problem in IDE 
  Problem in syntax

Accepted Answer

Problem arising during runtime

Question 44

[T / F] Objects of abstract superclasses can be instantiated.

Accepted Answer

False

Question 45

Which type of function among the following shows polymorphism?
  Inline function 
  Virtual function 
  Class member functions 
  Undefined functions

Accepted Answer

Virtual function

Question 46

[T / F] If we derive an abstract class and do not implement all the abstract methods, then the derived class should also be marked as abstract using 'abstract' keyword

Accepted Answer

False

Question 47

Which of the following classes fail to compile?
abstract class X { abstract void method(); }

class Y extends X { }

class Z extends Y { void method() { System.out.println("Class Z"); } }

  Y, Z
  Y
  Z
  X, Y, Z

Accepted Answer

Y

Question 48

What is an advantage of polymorphism
  Polymorphism is a dangerous aspect of inheritance and should be avoided. 
  Variables can be re-used in order to save memory. 
  The same program logic can be used with objects of several related types.

Accepted Answer

The same program logic can be used with objects of several related types.

Question 49

Which of the following classes fail to compile?
abstract class X { abstract void method(); }
abstract class Y extends X { }
class Z extends Y { void Method() { System.out.println("Class Z"); } }

  X, Y
  X, Y, Z
  Y
  Z

Accepted Answer

Z

Question 50

An exception may arise when _______________
  Input is fixed 
  Input given is invalid 
  Input is valid 
  Input is some constant value of program

Accepted Answer

Input is valid

Question 51

What is an exception?
  Problem in IDE 
  Problem arising during compile time 
  Problem arising during runtime 
  Problem in syntax

Accepted Answer

Problem arising during runtime

Question 52

[T / F] The programmer can choose to execute a return statement or to throw an exception if an assertion fails.

Accepted Answer

True

Question 53

[T / F] Conditional compilation is used to allow tested classes to run at full speed

Accepted Answer

False

Question 54

[T / F] Assertions are appropriate for checking the validity of arguments in a method.

Accepted Answer

False

Question 55

[T / F] Assertions can be enabled or disabled on a class-by-class basis.

Accepted Answer

False

Question 56

[T / F] If the Java program is using assertions, it must be run with -ea or -enableassertions switches.

Accepted Answer

False

Question 57

Which array declaration is correct that to hold up to 10 objects of types Rat, Mouse, and PocketMouse?
A) Rodent rodents[10];
B) Rodent[] array = new Rodent[10]; 
C) Rodent rodents = new Rodent[10];
D) Rodent[] rodents;

Accepted Answer

Rodent[] array = new Rodent[10];

Question 58

[T / F] All methods in a final class must be explicitly declared final.

Accepted Answer

False

Question 59

If 2 classes derive one base class and redefine a function of base class, also overload some operators inside class body. Among these two things of function and operator overloading, where is polymorphism used?

Accepted Answer

Function overloading only

Question 60

[T / F] A method that is declared final cannot be overridden in a subclass.

Accepted Answer

True

Question 61

What method of an Exception object prints a list of methods that were called before the exception was thrown?
  printStackTrace() 
  printErrors() 
  traceStack() 
  getMessage()

Accepted Answer

printStackTrace()

Question 62

Say that a method catches an IOException in a catch{} block. Is it possible for that block to do some processing and then throw the same exception to the caller?

Accepted Answer

Yes---as long as the method also has a throws clause for that exception.

Question 63

What happens during execution if an negative value is used for an array index?
  A NumberFormatException is thrown. 
  An IndexOutOfBoundsException is thrown. 
  The first slot of the array is used.

Accepted Answer

An IndexOutOfBoundsException is thrown.

Question 64

To catch the exceptions ___________________
  An array should be created to catch all the exceptions 
  An object must be created to catch the exception 
  A variable should be created to catch the exception

Accepted Answer

An object must be created to catch the exception.

"Know" box contains:
Time elapsed:
Retries:

CCS0070 FINALS