PRACTICE QUESTIONS ON ABSTRACT CLASS – CLASS MARKSHEET

An abstract class called “Marks” is needed to calculate the percentage of marks earned by students A in three subjects (with each subject out of 100) and student B in four subjects (with each subject out of 100). This class must contain the abstract method “getPercentage,” which two other classes, “A” and “B,” will inherit. The method “getPercentage,” which provides the percentage of students, is shared by classes “A” and “B.”

The constructor of class ‘A’ will accept the marks obtained in three subjects as its parameters and the constructor of class ‘B’ will accept the marks obtained in four subjects as its parameters. To test the implementation, objects for both the classes need to be created and the percentage of marks for each student should be printed.

abstract class Marks {
   abstract double getPercentage();
}

class A extends Marks {
   double subject1, subject2, subject3;

   A(double subject1, double subject2, double subject3) {
      this.subject1 = subject1;
      this.subject2 = subject2;
      this.subject3 = subject3;
   }

   double getPercentage() {
      double percentage = (subject1 + subject2 + subject3) / 3.0;
      return percentage;
   }
}

class B extends Marks {
   double subject1, subject2, subject3, subject4;

   B(double subject1, double subject2, double subject3, double subject4) {
      this.subject1 = subject1;
      this.subject2 = subject2;
      this.subject3 = subject3;
      this.subject4 = subject4;
   }

   double getPercentage() {
      double percentage = (subject1 + subject2 + subject3 + subject4) / 4.0;
      return percentage;
   }
}

public class AbstractExample {
   public static void main(String args[]) {
      A studentA = new A(80.0, 90.0, 95.0);
      B studentB = new B(70.0, 80.0, 90.0, 85.0);
      
      System.out.println("Percentage obtained by Student A: " + studentA.getPercentage());
      System.out.println("Percentage obtained by Student B: " + studentB.getPercentage());
   }
}

Save the above Program with “AbstractExample .Java” then compile it with the following command :

javac AbstractExample.java //to compile the code 

java AbstractExample //to run the code

Output is :

Percentage obtained by Student A: 88.33333333333333
Percentage obtained by Student B: 81.25

Want to practice more problems involving Abstract Classes? Click here.