class MyBook extends Book { void setTitle(String s) { title=s;

}

}

here is the simple solution https://github.com/csennn/java_abstract_class/blob/main/codes

import java.io.; import java.util.;

public class Solution {

public static void main(String []args){
    //Book new_novel=new Book();  Abstract cass cannot be instantiated like this
    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());

}

}

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

class MyBook extends Book{ void setTitle(String s){ title=s; } }

Here is problem solution - https://thecscience.com/hackerrank-java-abstract-class-problem-solution.html

The problem and what we need to do is defined nicely. As the abstract class is given we have to create MyBooks class that extends the abstract class. Now, as this is a child class, it will inherit all the properties of super class. So, I've just defined the body of the setTitle method here. And it's all.

//Write MyBook class here
class MyBook extends Book{
    void setTitle(String s){
        title = s;
    }
}