CBSE Class 12 C++ Practical - Class Design Snippet-1 (#cbseNotes)

C++ Practical
Class Design Snippet-1

Question 1: Imagine a publishing company that markets both book and audio-cassette versions of its works. Create a class publication that stores the title (a string) and price (type float) of a publication. From this class derive two classes: book, which adds a page count (type int) and tape, which adds a playing time in minutes (type float). Each of these three classes should have a getdata() function to get its data from the user and a putdata() function to display its data. Write a main() program to test the book and tape classes by creating instances of then displaying the data with putdata().


Answer:

#include<iostream.h>
#include<string.h>
#include <conio.h>
#include <stdio.h>
#define max 100

void flushkb();

class publication        
   { 
   protected:
 char title[max];
 float price;
    public:
    publication( )
 {
    strcpy(title,"");
    price=0.0;
 }

 publication(char t[],float pr)
 {
     strcpy(title,t);
     price=pr;
 }

 void getdata( )
 {
     cout<<"Enter title:";
     cin.get(title,max);
     cout << "Enter price:";
     cin>>price;
     //cin.ignore(1, '\n');
 }

 void putdata( )
 {
    cout<<"Title:"<< title<<"\tPrice:"<<price<<"\t";
 }
    };

class Book : public publication
   {
   private: int pgcount;
   public:
       Book( ): publication( )
 {
 pgcount=0;
 }

 Book(char t[],float pr,int pgc): publication(t,pr)
 { pgcount=pgc;   }

 void getdata( )
 {
     publication::getdata( );
     cout<<"Enter pagecount:";
     cin>>pgcount;
 }

 void putdata()
 {
    publication:: putdata();
    cout << "Page Count:" << pgcount << "\n";
 }
   };

class tape: public publication
   {
   private:
 float min;
   public:
       tape()
 { min =0.0;   }

 void getdata( )
 {
     cin.ignore(3, '\n');
     publication::getdata( );
     cout<<"Enter minutes:";
     cin>>min;
 }

 void putdata( )
 {
    publication::putdata( );
    cout<<"minutes:" << min<<"\n";
 }
   };

void main( )
   {
  clrscr();
  Book B;
  B.getdata( );
  B.putdata( );
  tape t;
  t.getdata( );
  t.putdata();
  getch();
   }

void flushkb()
{
  char ch;
  while ((ch =getchar()) != '\n' && ch != EOF)
    continue;
}