Java programming final test

Answer 1

Can you answer in this java programming quiz? just 1 or 2 answers are fine..

1. The != operator is used to evaluate _______ between two values.

Non-equality

!!

=!

Equality

2. The interface part of a class is created using

package access

protected visibility

private visibility

3. User defined data type or objects (like a Car class object) are passed by

Reference

Value

Copy

Placement

5 . If you declare constructors private, they ________ be called by all classes and methods to create objects.

Can

can privately

can virtually

Can t

6. Components are placed in a container by calling the __________ method.

registerComponent ()

addActionListener ()

setLayout ()

add ()

7. If an abstract method is not defined in a subclass, the subclass is

Abstract

Overridden

Promoted to the superclass

Hidden

8. Subclass objects of different type that inherit from the same superclass

Can be treated as superclass objects

Can't share private superclass data

Don't share the same superclass data

Don't share any data

9. Polymorphism

Promotes and allows sharing of data and methods between classes

Allows development of general solutions and the runtime selection of methods

Prevents methods outside a class from directly accessing instance variables

Allows classes to contain/combine both data (properties) and methods (behaviors)

10. Inheritance relationships form _________.

Hierarchical Structures

Peer to Peer Networks

Loosely bounded sets

Network Structures

11. Your program class that inherits from JPanel ____________.

Uses a constructor to initialize objects

Inherits the behavior of a JObject program

Is unable to override paint_component ()

Knows nothing of drawing

12. The paint_component method ___________.

Must be private

Expects a Graphics object argument

Never calls super.paint_component (g)

Must be called by you

13. Successful use of polymorphism depends on

Identifying generic methods

Identifying an inheritance class composition

Identifying abstract objects

Deciding on how to use subclass references

14. A superclass method can be overridden in a subclass in order to

Change the name

Make the method private

Provide new behavior appropriate to the subclass

Allow hidden access

16 . In order to place subclass objects of different type in an array

They must inherit from the same subclass

The array reference itself must be of superclass type

You must cast and add-in missing superclass members

They must be of the same type

17. The name of the event handler method of the ActionListener interface is ____.

itemStateChanged

mouseMoved

actionPerformed +

keyPressed

18. Downcasting

Converts a subclass reference to a superclass reference

Converts a subclass object to a superclass object

Converts a superclass reference to a subclass reference

Converts a superclass object to a subclass object

19. A simple layout manager is the ____ manager.

GridLayout

BoxLayout

FlowLayout

PanelLayout

20. An individual array element is accessed using its _________.

Type

Subscript/Index

Value

Object

21. Since it generates byte codes, the Java compiler is _________.

An interpreter

Not a true compiler

Object code

Windows instructions

22. When GUI components are displayed on the screen, a/an ___________ positions and displays those components.

Layout manager

Container object

Event handler

Interface class

23. An executing program class must contain a/an

Body

Main method

Instance variable

Comment

24. Referring to a superclass object through a subclass reference

Can cause a runtime error

Requires that the superclass reference refers to the same subclass object as the cast

Requires an explicit object to avoid the compilation error

25. Polymorphism works for

Unrelated classes

Overloaded classes

An inheritance hierarchy of classes

Has-a classes

26. Given that a=4, b=10, c=2, d=5, and x=3, the expression "(a + c) / c * d + a" evaluates to

20

4

128

19+

27. When dynamic binding takes place, the Java system

Determines the type of the object at compile time

Binds a method name to its address at runtime

Moves up the inheritance hierarchy

Makes a list of generic event handlers

28. When dynamic binding takes place, the Java system

Determines the type of the object at compile time

Binds a method name to its address at runtime

Moves up the inheritance hierarchy

Makes a list of generic event handlers

29. If a subclass constructor explicitly calls a superclass constructor

It overrides the superclass constructor

It must call the noarg constructor

It cannot access protected data

The call must be the first line of code

30. The composition relationship can be identified as a/an _________ relationship.

Enduring

Has/a

Is/a

Overridden

31. When declared with a static lifetime,

Variables exist during the execution of a method

Variables exist from beginning to end of program execution

Methods and instance variables are visible

Variables declared outside the {} of a block

32. When an array is passed as an argument to a method, _____.

The array is passed by reference

Only the first value is passed

The called method can't change array values

It is passed by value

33. When the expression "result = total + input * 2;" is evaluated the __________ is placed in the location of the left hand side.

Left side result

Assignment

Right side result

Operator

34. When invoked, a subclass constructor

Automatically calls the noarg constructor of the superclass (if one is not explicitly called)

Cannot access superclass data even if protected

Returns a superclass object

Does not use the superclass constructor

35. When declared with automatic scope,

Variables exist during the execution of a method

Variables exist from beginning to end of program execution

Methods and instance variables are visible

Variables declared outside the {} of a block

36. The inheritance class relationship

Promotes and allows sharing of data and methods between classes

Allows development of general solutions and the runtime selection of methods

Prevents methods outside a class from directly accessing instance variables

Allows classes to contain/combine both data (properties) and methods (behaviors)

37. When a subclass method has the same name and type as a superclass method but accepts different arguments, that's an example of

Protected inheritance

Overriding

Polymorphism

Overloading

38. When you want to declare constant values, you would use the ________ keyword.

objects

final

const

Static variables

39. The toString method

Is not provided by class Object

Is called implicitly to convert an object to a String

Can be overloaded

Can't be overridden

40. A switch statement tests a variable or expression against __________.

Constant, integral values

Expressions

Decimal numbers

Strings

41. Reffering to a superclass object through a subclass reference

can cause a runtime error

Requires that the superclass reference refers to the same subclass object

Requires an explicit object to avoid the compilation error

48. Because all variables must be declared before their use, Java

Is an object oriented language

Is a strong variable language

Is a strongly typed language

Is a typing language

49. Variables declared/defined inside a method are

General variables

Visible everywhere

Local variables

Instance variables

50. The while statement

Is the most specific form of repetition

Requires initialization, test, and change of a control variable

Will never skip execution of the loop body

Doesn't use a control variable

51. The do-while statement

Does not require a test of cond

Is the most specific form of repetition

Executes at least once

Is intended to replace for statements

52. The use of superclass references to refer to subclass objects has been found useful

For container objects

When placing elements of subclass objects in a superclass array

When placing elements of superclass objects in a subclass array

For Composition classes

53. Overloaded constructors are used to

Create different types of objects

Create two dimensional arrays

Create primitive data types

Initialize objects of the same class in different ways

54. Java's mechanism for placing related classes in a subdirectory uses the ________ keyword.

package

import

extensible

extends

55. this

is a reference to an object

Can t be used to access object data

Is passed to every class

Is hidden and private

56. An anonymous inner class ____.

Has a class name

Typically is used to define an event handler class

Has no scope

Contains anonymous methods

57. The new operator is used to __________.

Allocate memory for an object or array

Call an object destructor

Call the garbage collector

Promote visibility

58. The drawOval method takes the same four arguments as ________.

drawLine ()

drawPoly ()

drawRect ()

fillArc ()

59. In order for a class method to access the private data of a class object (not of its class)

The data can only be read

It can't

The data can be changed directly

get/set methods must be used

Question 62

62. Class methods ________ access all class variables, public or private.

Can

Can't

64. A reference in a Java program

Causes object initialization

Refers or points to a runtime data type

Causes memory allocation

Refers (or points to) to an object

65. The listener interface for radio buttons is the ____ interface.

ActionListener

MouseListener

KeyListener

ItemListener

66. implementation part of a class is created using

67. What types of superclass methods/variables can be directly accessed from a sub class?

public

private

provoked

68. The statement(s) in the body of an if structure should be indented in order to

Compile properly

They shouldn t

Stand out and enhance readability

Allow repetition

69. The sdk program that is the JVM and runs programs is

java

javac

appletviewer