OOP 3

 Imagine a publishing company which does marketing for book and audio cassette versions. Create a class publication that stores the title (a string) and price (type float) of publications. 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). Write a program that instantiates the book and tape class, allows user to enter data and displays the data members. If an exception is caught, replace all the data member values with zero values.

The code for above problem is as follows:

   
 //@author: SPPU CSE GURU  
   
 #include <iostream>  
  using namespace std;  
  class Publication  
  {  
       private:  
            string title;  
            float price;  
       public:  
       Publication()               //constructor  
       {  
            title="";  
            price=0.0;  
       }  
       Publication(string title, float price)  
       {  
            this->title=title;  
            this->price=price;  
       }  
         
       void getData()  
       {  
            cout<<"\nEnter title and price\n";  
            cin>>title>>price;  
       }  
         
       void putData()  
       {  
            try  
            {  
                 if(title.length()<3)  
                      throw title;  
                        
                 if(price<=0.0)  
                      throw price;  
            }  
            catch(string)  
            {  
                 cout<<"\nError: Title below 3 characters is not allowed";  
                 title="";  
            }  
              
            catch(float f)  
            {  
                 cout<<"\nError: Price not valid: \t"<<f;  
                price=0.0;  
            }       
            cout<<"\nTitle is :"<<title;  
            cout<<"\nPrice is :"<<price;  
       }  
         
  };  
    
    
  class Book: public Publication  
  {  
       private:  
            int pages;  
       public:  
            Book():Publication()  
            {  
                 pages=0;  
            }  
            Book(string title, float price, int pages):Publication(title,price)  
            {  
                 this->pages=pages;  
            }  
              
       void getData()  
       {  
           Publication::getData();  
            cout<<"\nEnter no. of pages in book\n";  
            cin>>pages;  
       }  
         
       void putData()  
       {  
            Publication::putData();  
            try  
            {  
                 if(pages<0)  
                      throw pages;  
            }  
            catch(int f)  
            {  
                 cout<<"\nError: Pages not valid: \t"<<f;  
                 pages=0;  
            }  
         
       cout<<"\nPages are :"<<pages;  
       }  
         
   
  };  
    
  class Tape: public Publication  
  {  
       private:  
            float playtime;  
       public:  
       Tape():Publication()  
       {  
            playtime=0.0;  
      }  
       Tape(string title, float price, float playtime):Publication(title,price)  
       {  
            this->playtime=playtime;  
       }  
         
       void getData()  
       {  
            Publication::getData();  
            cout<<"\nEnter play time of Tape\n";  
            cin>>playtime;  
       }  
         
       void putData()  
       {  
            Publication::putData();  
            try  
           {  
                 if(playtime<0.0)  
                      throw playtime;  
            }  
            catch(float f)  
            {  
                 cout<<"\nError: Playtime not valid: \t"<<f;  
                 playtime=0.0;  
            }  
            cout<<"\nPlaytime is :"<<playtime;  
       }  
         
        
  };  
    
  int main()  
  {  
       Book book;  
      Tape tape;  
       cout<<"\n***************BOOK**************\n";  
       book.getData();  
       cout<<"\n***************TAPE**************\n";  
      tape.getData();  
       cout<<"\n***************BOOK**************\n";  
       book.putData();  
       cout<<"\n***************TAPE**************\n";  
       tape.putData();  
       return 0;  
  }