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Unsolved Questions



                 A.  Tick ( ) the correct option:
                    1.  BufferedReader class belongs to package ………………… .
                       a.  util                                        b.  IO
                       c.  lang                                        d.  io
                    2.  Which of the following is not an advantage of using a package?
                       a.  Polymorphism                                b.  Eliminates naming collision
                       c.  Provides access protection                  d.  Reusability
                    3.  To access class CompProj  in package  mypackage, we write ………………… .
                       a.  import CompProj.mypackage;                  b.  import mypackage.CompProj;
                       c.  package CompProj.mypackage;                 d.  package  mypackage.CompProj;
                    4.  Which of the following is defined as a blueprint or prototype of similar objects?
                       a.  String                                      b.  class
                       c.  package                                     d.  mysql
                    5.  Which of the following options contains classes and packages that are helpful in minimising and simplifying Java coding, like java.
                       lang, java.util, java.io, etc.?
                       a.  JDK                                         b.  API
                       c.  Packages                                    d.  StringTokenizer

                 B.  Fill in the blanks:

                    1.  Full form of API  is ………………… .
                    2.  ………………… access must be given to access a class from a different package.

                    3.  To use StringTokenizer class we have to import ………………… .
                    4.  To create a new package in BlueJ choose ………………… option on BlueJ menu and from the drop-down list click ………………… .

                    5.  The packages already defined in Java software are known as …………………  packages.
                 C.  Answer the following questions:
                    1.  What is a package? Write two advantages of using package.
                    2.  Name any two built-in packages and write their functions.
                    3.  Write how public access works in:
                       a.  same class                                  b.  same package
                       c.  subclass outside package                    d.  outside package
                    4.  What are user-defined packages?
                    5.  How can we access any package?
                                                                                      #Coding & Computational Thinking
                 D.  Unsolved Programs:                                               #Interdisciplinary
                    1.  Write a program to create a package Comprac containing class CountDig having the following specifications.
                       Package                                       :  Comprac
                       Class name                                    :  CountDig
                       Data Members
                       int n                                         :  Stores number as binary
                       Member Methods
                       CountDig(int x)                               :  Constructor to assign the data members
                       int count()                                   :  Counts and returns number of 1’s in a binary number
                       Write a second class Odious in package Green to import class CountDig of package Comprac and use the method count() to print
                       if a number is an odious number or not. An Odious number is a non-negative number that has an odd number of 1s in its binary
                       expansion.


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