have written a superclass, main class and 2 subclasses, but I did error in diffe

Question

have written a superclass, main class and 2 subclasses, but I did error in different parts so I want know where my errors are.

1st subclass = book subclass

2nd subclass = CD subclass

The superclass consists of: title,price, year

The super class should :initialize title,price, year

                                             raise the price to 10%

                                             tell the user how to use the publication to look up a specific topic.(it will be bstract).

That's what I have for superclass so far:

public abstract class superclass

{
protected String title;
protected double price;
protected int year;

public superclass(String t, int y)
{
    title = t;
    price *= 0.1;
    year = y;
}



public void print()
{
    System.out.print("Title is" + title);
    System.out.printf("Price is = %.2f " , price);
    System.out.print("Publication Year is " + year);
}

public abstract String getsuperclassinfo();
}

HELP ME IF I DID ANY ERRO AND GUIDE ME THROUGH BOOK,CD SUBCLASSES AND MAIN CLASS:

BOOK SUBCLASS:

use what inherited

and has a number of pages

use method to tell user to look up their topic in the table of contents

print method will label the output as a book and print all labeled data fields (use publication's print method for title,price,year)

CD SUBCLASS

use what inherited: title,price,year

also has a number of minutes

use method to tell the user to look up their topic on the cd

print method ==label output as CD and print all labeled data fields

MAIN CLASS:

ask user for how many publications there are.

declare array of abstract super references of publication of the # of publications.

use for loop

prompt and input all data fields (ask user what kind of publication for what added data to input and take upper or lowercase)

create object and assign it into the next reference in the array

start another for loop

call method to raise each of publication ref. by 10%

print method with dynamic method bindin for each of the publication references

use method with dynamic method binding for each of the publication references.

The Data should be entered as follows:

Input:

Enter number of publications

Enter title

Enter price

Enter publication year

Is publication a boook or cd

enter pages

enter title

enter price

enterpublication year

is publication a book or cd

enter minutes

output:

Book

Title is...

Price is

publication year is

number of pages is

open book to table of contents

look up topic and turn to corresponding page

CD

title is

price is

publication year

number of minutes

look on cd to find topic number

skip to correspondin section

Explanation / Answer

import java.util.*;
abstract class superclass
{
protected String title;
protected double price;
protected int year;
public superclass(String t, int y,double p)
{
    title = t;
    price = p;
    year = y;
}
public void print()
{
    System.out.println(" Title is " + title);
    System.out.printf("Price is = %.2f " , price);
    System.out.println("Publication Year is" + year);
}
public abstract String getpublicationinfo();
public abstract void look_into_contents();
}

class book extends superclass
{
private int no_of_pages;
public book(String t,int y,double p,int no)
{
super(t,y,p);
no_of_pages = no;
}
public void print()
{
super.print();
System.out.println("This book has number of pages " + no_of_pages);
}
public void look_into_contents()
{
System.out.println("look up their topic in the table of contents");
}
public void raise_price()
{
price*=1.1;
}
public String getpublicationinfo()
{
return ("Title is" + title);
}
}

class CD extends superclass
{
private int no_of_minutes;
public CD(String t,int y,double p,int no)
{
super(t,y,p);
no_of_minutes = no;
}
public void print()
{
super.print();
System.out.println("This CD has number of minutes " + no_of_minutes);
}
public void look_into_contents()
{
System.out.println("look up their topic on CD ");
}
public void raise_price()
{
price*=1.1;
}
public String getpublicationinfo()
{
return ("Title is" + title);
}
}

public class Main
{
public static void main(String[] args)
{
Scanner in = new Scanner(System.in);
System.out.println(" How many total publication u have? ");
int no = in.nextInt();
superclass[] array = new superclass[no];
for(int i=0; i<no; i++)
{
System.out.println("Enter title");
String title = in.next();
System.out.println("Enter price");
double price = in.nextDouble();
System.out.println("Enter publication year");
int year = in.nextInt();
System.out.println("Is publication a boook or cd");
String book_or_cd = in.next();
if(book_or_cd.equalsIgnoreCase("book"))
{
System.out.println("enter pages");
array[i] = new book(title,year,price,in.nextInt());
}
else if(book_or_cd.equalsIgnoreCase("CD"))
{
System.out.println("enter minutes");
array[i] = new CD(title,year,price,in.nextInt());
}
}
for(int i=0; i<no; i++)
{
array[i].print();
array[i].look_into_contents();
}


}
}

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