Page 489 - Computer science 868 Class 12
P. 489

code                                      :  integer to store the item code
                        amount                                    :  stores the total sale amongst the item (in decimals)
                        Member Functions/Methods
                        item(...)                                 :  parameterised constructor to assign value to the data members
                        void show()                               :  to display the item details
                        Class name                                :  Taxable
                        Data Member/Instance variables

                        tax                                       :  to store the service tax (in decimals)
                        totamt                                    :  to store the total amount (in decimals)
                        Member Functions/Methods
                        Taxable(...)                              :   parameterised constructor to assign values to the data members
                                                                    of both classes
                        void cal_tax()                            :  calculates the service tax @ 10.2% of the total sale amount
                                                                     calculates  the total amount paid  by the retailer as (total sale
                                                                    amount + service tax)

                        void show()                               :   to display the item details along with the total amount
                        Assume that the class Item has been defined. Using the concept of inheritance, specify he class Taxable, giving details of the
                       constructor, void cal_tax() and void show().
                        The super class, main function and algorithm need NOT be written.
                   Ans.  class Taxable extends Item
                       {
                          double tax,totamt;
                          Taxable(String n,int c,double amt)
                          {
                            super(n,c,amt);
                            tax=0.0;
                            totamt=0.0;
                          }
                          void cal_tax()
                          {
                            tax=amount*10.2/100;
                            totamt=amount+tax;
                          }
                          void show()
                          {
                            super.show();
                            System.out.println("Service Tax : "+tax);
                            System.out.println("Total Amount : "+totamt);
                          }
                       }
                    7.  An interface Data is defined with a data member and a method volume( ) which returns the volume of the implementing
                       shape. A super class Base has been defined to contain the radius of a geometrical shape. Define a sub class CalVol which uses
                       the properties of the interface Data and the class Base and calculates the volume of a cylinder.
                        The details of the members of the interface and both the classes are given below.        [ISC 2020]
                        interface name                    :  Data
                        Data Members
                        double pi                         :   initialise pi = 3.142
                        Member Functions
                        double volume()                   :   Abstract method


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