Java Abstract Class-HackerRank Solution

A Java abstract class is a class that can't be instantiated. That means you cannot create new instances of an abstract class. It works as a base for subclasses. You should learn about Java Inheritance before attempting this challenge.

Following is an example of abstract class:

 

  abstract class Book{
  String title;
  abstract void setTitle(String s);
  String getTitle(){
  return title;
    }
  }

If you try to create an instance of this class like the following line you will get an error:

  Book new_novel=new Book();

 

You have to create another class that extends the abstract class. Then you can create an instance of the new class.

Notice that setTitle method is abstract too and has no body. That means you must implement the body of that method in the child class.

In the editor, we have provided the abstract Book class and a Main class. In the Main class, we created an instance of a class called MyBook. Your task is to write just the MyBook class.

Your class mustn't be public.

Sample Input

 

  A tale of two cities

Sample Output

  The title is: A tale of two cities

Solution

 

  import java.util.*;
  abstract class Book{
  String title;
  abstract void setTitle(String s);
  String getTitle(){
  return title;
   }
  }

  //Write MyBook class here
  class MyBook extends Book{

  void setTitle(String s){
  title=s;

  }

  }

  public class Main{

  public static void main(String []args){

  Scanner sc=new Scanner(System.in);
  String title=sc.nextLine();
  MyBook new_novel=new MyBook();
  new_novel.setTitle(title);
  System.out.println("The title is: "+new_novel.getTitle());
  sc.close();

   }
  }

Abstract Class in Java does the process of hiding the intricate code implementation details from the user and just provides the user with the necessary information. This phenomenon is called Data Abstraction in Object-Oriented Programming