Question

Given main() and a base Book class, define a derived class called Encyclopedia. Within the derived Encyclopedia class, define a printInfo() method that overrides the Book class' printInfo() method by printing not only the title, author, publisher, and publication date, but also the edition and number of volumes. Ex. If the input is: The Hobbit J. R. R. Tolkien George Allen

Answer 1

Answer:    

Here is the Encyclopedia class:

public class Encyclopedia extends Book {   //class  Encyclopedia that inherits from class Book

  private String edition; //declare private member variable edition of type String  

  private int numVolumes;      //declare private member variable numVolumes of type int

  public void setEdition(String ed) {  //mutator method of class that sets the value of edition

     edition = ed;    }     //assigns the value of ed to edition member field

  public void setNumVolumes(int numVol) { //mutator method of class that sets the value of numVol

     numVolumes = numVol;    }  //assigns the value of numVolumes to edition member field

  public String getEdition() {  //accessor method to get the value of edition

     return edition;    }     //returns the current value of edition

  public int getNumVolumes() {  //accessor method to get the value of numVolumes

     return numVolumes;    }       //returns the current value of numVolumes

  public void printInfo() {  //method to print edition and number of volumes information on output screen

     super.printInfo();  // The super keyword refers to parent class Book objects. It is used to call Book method and to eliminate the confusion between Book class printInfo method and Encyclopedia printInfo  method

     System.out.println("   Edition: " + edition);  //prints edition info

     System.out.println("   Number of Volumes: " + numVolumes);    }  }  //prints number of volumes info

Explanation:

The explanation is provided in the attached document.