Deck 10: Java Programming Language: Inheritance, Interfaces, Packages, and Methods

Question 1

Which of these is correct way of inheriting class A by class B?

A)class B + class A {}
B)class B inherits class A {}
C)class B extends A {}
D)class B extends class A {}

Answer 1

class B extends A {}

Question 2

Which of the following are true about interfaces.

A)Methods declared in interfaces are implicitly private.
B)Variables declared in interfaces are implicitly public, static, and final.
C)An interface contains any number of method definitions.
D)The keyword implements indicate that an interface inherits from another.

Answer 2

Variables declared in interfaces are implicitly public, static, and final.

Question 3

Which of the following is correct way of implementing an interface salary by class manager?

A)class Manager extends salary {}
B)class Manager implements salary {}
C)class Manager imports salary {}
D)None of the mentioned.

Answer 3

class Manager implements salary {}

Question 4

Which of the following is incorrect statement about packages?

A)Package defines a namespace in which classes are stored.
B)A package can contain other package within it.
C)Java uses file system directories to store packages.
D)A package can be renamed without renaming the directory in which the classes are stored.

Question 5

Which exception is thrown by read() method?

A)IOException
B)InterruptedException
C)SystemException
D)SystemInputException

Question 6

Which method in Thread class is used to check weather a thread is still running?

A)isAlive()
B)Join()
C)isRunning()
D)Alive()

Question 7

Which of these class contains the methods print() & println()?

A)System
B)System.out
C)BufferedOutputStream
D)PrintStream

Question 8

To design a general-purpose search method, searchList, to search a list, which of the following must be parameters of the method searchList?
(i) The array containing the list.
(ii) The length of the list.
(iii) The search item.
(iv) A boolean variable indicating whether the search is successful.

A)(i) and (ii)
B)(i), (ii), and (iii)
C)(ii), (iii), and (iv)
D)(i), (ii), (iii), and (iv)

Question 9

In which package is the class Vector located?

A)java.io
B)java.lang
C)java.util
D)java.text

Question 10

For the interface WindowListener that contains more than one method, Java provides the class ____.

A)MouseAdapter
B)WindowAdapter
C)KeyListener
D)KeyAdapter

Question 11

Consider the following list. int[] intList = {35, 12, 27, 18, 45, 16, 38}; What is the minimum number of comparisons that have to be made to find 18 using a sequential search on intList?

A)1
B)2
C)3
D)4

Question 12

Which of these packages contains all the classes and methods required for even handling in Java?

A)java.applet
B)java.awt
C)java.event
D)java.awt.event

Question 13

What is an event in delegation event model used by Java programming language?

A)An event is an object that describes a state change in a source.
B)An event is an object that describes a state change in processing.
C)An event is an object that describes any change by the user and system.
D)An event is a class used for defining object, to create events.

Question 14

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

A)KeyListener()
B)addKistener()
C)addKeyListener()
D)eventKeyboardListener()

Question 15

Which of these methods are used to register a mouse motion listener?

A)addMouse()
B)addMouseListener()
C)addMouseMotionListner()
D)eventMouseMotionListener()

Question 16

What is a listener in context to event handling?

A)A listener is a variable that is notified when an event occurs.
B)A listener is a object that is notified when an event occurs.
C)A listener is a method that is notified when an event occurs.
D)None of the mentioned

Question 17

Which command disassembles a class file

A)javaamd
B)javacmd
C)java
D)javap

Question 18

Which of the following statements is false as far as different type of statements is concern in JDBC?

A)Regular Statement
B)Prepared Statement
C)Callable Statement
D)Interim Statement