Java/com/study/demo3/PrintedBook.java

package com.study.demo3;

public class PrintedBook extends Book {
  private int stock;

  public PrintedBook() {
    super();
  }

  public PrintedBook(String isbn, String title, int stock) {
    super(isbn, title);
    this.stock = stock;
  }

  public int getStock() {
    return stock;
  }

  public void setStock(int stock) {
    this.stock = stock;
  }

  @Override
  public String toString() {
    return "PrintedBook [ISBN="
        + isbn
        + ", Title="
        + title
        + ", Stock="
        + stock
        + ", Available="
        + available
        + "]";
  }
}