Book

public class InheritanceIntro {

    public static void main(String[] args) {
        Book a = new Book("David Copperfield", "Charles Dickens",800);
        System.out.println(a);
        System.out.println(a.getAuthor());
        System.out.println(a.isLong());
        Book b= new Book("The Cat in the Hat", "Dr.Seuss", 28);
        System.out.println(b.isLong());
        LibraryBook c= new LibraryBook("It", "Stephen King",1050,"kin it");
        System.out.println(c.getTitle());
        Book d = new LibraryBook();
        //LibraryBook e = new Book();
        System.out.println(c);
        d.setTitle("Moby Dick");
        System.out.println(d.getTitle());
        Ebook f = new Ebook("Less Than Zero","Bret Easton Ellis", 470);
        for (int i=1; i<f.getPages();i++) {
            f.turnPage();
        }
        System.out.println(f.page);


    }

}
class Book{
    // instance variables or data fields
    private String title;
    private String author;
    private int pages;

    public Book() {

    }
    public Book(String title, String author,int pages) {
        this.title =title;
        this.author=author;
        this.pages=pages;
    }
    public String getTitle() {
        return title;
    }
    public String getAuthor() {
        return author;
    }
    public int getPages(){
        return pages;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    public void setAuthor(String author) {
        this.author=  author;
    }
    public void setPages(int pages) {
        this.pages = pages;
    }
    public boolean isLong() {
        if (pages >= 500)
            return true;
        else
            return false;
    }
    public String toString() {
        return title + " by author "+ author + " is "+ pages +" pages";
    }
}
class LibraryBook extends Book{
    private String callNumber;
    private String isPresent;

    public LibraryBook() {
        super();
        isPresent = true;
    }
    public LibraryBook(String title, String author,int pages, String callNumber) {
        super(title, author, pages);
        this.callNumber = callNumber;
        isPresent = true;
    }
    public void checkedOut() {
        isPresent = false;
    }
    public void checkedIn() {
        isPresent = true;
    }
    public String toString() {
        if(checkedIn)
        return super.toString() + " \n with call number "+ callNumber + ".  The book is in the library.";
        return super.toString() + " \n with call number "+ callNumber + ".  The book is checked out.";
    }
    }
    class Ebook extends Book{
        private int page = 1;
        public Ebook() {
            super();
        }
        public Ebook(String title, String author, int pages) {
            super(title, author, pages);

        }
        public void turnPage() {
            if (page == getPages())
                page = 1;
            else
            page++;
        }
        public void turnBack() {
            if (page == 1) {
                }
            else
            page--;
        }

    }