Confuse Skull: JAVA MCQ's

JAVA MCQ's

1. how will a class protect the code inside it?

Using Access specifiers

2. the set interface model the ____ set abstractionand is used to represent sets,such as the deck of cards.

Duplicate (doubted)

3. inheritance represent the ___ relationship,also known as parent-child relationship.

IS-A

4. What is ‘Basis of Encapsulation’?

all of the mentioned

5. which of these is an correct way of defining generic class?

class name{/..../}

6. Which of these events will be notified if scroll bar is manipulated?

AdjustmentEvent

7. which of these class is not a member class of java.io package?

string

8. Which of these methods deletes all the elements from invoking collection?

clear()

9. Which of these is method is used for writing bytes to an outputstream?

write() print()

10. .the conditional operator has it has three operands -- and it comes in two pieces, ? and :, that have to be used together.

It takes the form

11. is the super class of all unchecked exceptions?

exception

12. What is Collection in Java?

A group of objects

13. inheritance is used for getting the properties from one class object to another class object level wise with different priorities

Multilevel

14. Which of these methods can be used to determine the type of event?

getID()

15. Which of these methods are used to register a keyboard event listener?

addKeyListener()

16. .Which of these is correct way of calling a constructor having no parameters, of superclass A by subclass B?

super();

17. Which of these access specifiers can be used for an interface?

public

18. list access any element from its

Index

19. what is the most important feature of java

oop

20. the concept of overloading contains the same name with?

static parameter

21. ______is a java way to convey both system and programming errors

Exception

22. Which of the following reference types cannot be generic?

Anonymous inner class

23. Which of these type parameters is used for a generic class to return and accept any type of object?

True

24. java doesn't support ____inheritence

Multiple

25. if a class defined by the code does not have any constructor ____ will automatically provide one no-parameter-constructor

compiler

26. what is true about a method local inner class

Must Mark as abstract

27. Which of these keywords can be used to prevent Method overriding?

final

28. java source code is complied into

byte code

29. The File class contains a method that changes the current working directory.

False

30. Which of these keywords is used by a class to use an interface defined previously?

implements

31. runnable interface is used in java for implementing applications

single threads

32. the keyword says to the jvm warning this variable may be modified in another

thread volatile

33. Which of these events will be generated if we close an applet’s window?

window event

34. Which of these classes is not part of Java’s collection framework?

map

35. Which of these packages contain all the collection classes?

util

36. Which of these class relies upon its subclasses for complete implementation of its methods?

abstract class

37. main method doesn't return anything and hence they declared as

void

38. ava uses data types and hence is not a pure oop

Primitive

39. the ordering maintained by a set must be with equals if it is to correctly implement the self interface

tree set

40. set is a collection that cannot contain which elements

list

41. Event class is defined in which of these libraries?

java.util

42. jvm is an abstract machine it is a specification that provides runtime environment in which java

byte

43. the conditional operator are called as

ternanry

44. list access any element from its

get

45. java allows you to control access to classes methods and fields via

access

46. which of these keywords is used to refer to member of base class from a sub class?

super

47. A class member declared protected becomes member of superclass of which type ?

private

48. which of these keyword can be used in subclass to callthe constructor of superclass?

super

49. the modifier keyword makes that the programmer cannot change the value anymore ?

final

50. jar stand for

java archive

51. which of these is the functionality of encapsulation?

Binds together code and data

52. which of these are selection statement in java?

if()

53. which of these operators is used to allocate memory for an object?

new

54. which of the following tool used to execute java code ?

java

55. the wrapping up of data and functions into a single unit is called

encapsulation

56. in java the inheritance can not extend more than one classes , this can be done by using ?

interface

57. jvm jre and jdk are because configurationof each os differs?

platform dependent

58. which statement is true regarding an object?

An object is an instance of a class

59. correct way of inheriting class A by class b?

class b extends A{}

60. literally means taking more then one from. ?

polymorphism

61. runtime polymorphism is also knowm as

method overriding

62. which of the following is not a keyword in java?

enum

63. is a collection of related class and interfaces?

package

64. what is the base class of all class in java?

java.lang.object

65. Which of the following concept is often expressed by the phrase, ‘One interface, multiple methods’?

polymorphism

66. whenever you write java cammand on the cammand prompt to run the _____?

java class

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