Question

write Java program has two classes ,( using Inheritance )

first class set ( id , name ) and method output

second class ( id , name , Mark 1 , Mark 2 , Mark 3 )

method total , average , grade , results ( if the student pass or not ) , and output method

Answer 1

The program is as follows:

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import java.util.*;

class Student
{
    int id;
    String name;
  
    public void setName(String name) //setter method for name
    {
        this.name=name;
    }
  
    public void setID(int id) //setter method for id
    {
        this.id=id;
    }
  
    public void getDetails() // method to retrieve the student details
    {
        System.out.println("*******Student Details*******");
        System.out.println("Student ID = "+id);
        System.out.println("Student Name = " +name);
    }
}

class StudentMarks extends Student
{
    float mark1;
    float mark2;
    float mark3;
  
    public void setMarks(float m1,float m2,float m3)
    {
        mark1=m1;
        mark2=m2;
        mark3=m3;
    }
  
    public float total()
    {
        return mark1+mark2+mark3;
    }
  
    public float average()
    {
        float avg= (mark1+mark2+mark3)/3;
        return avg;
    }
  
    public void grade() // grading is done individually for each subject
    {
        int i=1;
        float marks = 0;
        while(i<=3)
        {
            System.out.print("Subject " + i + ": ");
            if (i==1)
            {
                marks = mark1;
            }
            else if (i==2)
            {
                marks = mark2;
            }
            else
            {
                marks = mark3;
            }
            if(marks<40)
            {
                System.out.println("Grade F");
            }
            else if(marks>=40 && marks<60)
            {
                System.out.println("Grade D");
            }
            else if(marks>=60 && marks<70)
            {
                System.out.println("Grade C");
            }
            else if(marks>=70 && marks<80)
            {
                System.out.println("Grade B");
            }
            else if(marks>=80 && marks<90)
            {
                System.out.println("Grade A");
            }
            else
            {
                System.out.println("Grade A+");
            }
            i++;
        }
    }
  
    public void results() // results is displayed individually for each subject
    {
        if(mark1 < 40)
        {
            System.out.println("Subject 1: Fail");
        }
        else
            System.out.println("Subject 1: Pass");
          
        if(mark2 < 40)
        {
            System.out.println("Subject 2: Fail");
        }
        else
            System.out.println("Subject 2: Pass");
          
        if(mark3 < 40)
        {
            System.out.println("Subject 3: Fail");
        }
        else
            System.out.println("Subject 3: Pass");
    }
  
    public void getDetails()
    {
        super.getDetails(); // calling the base class getDetails() function to print student name and id
        System.out.println("Subject 1 Marks: " +mark1);
        System.out.println("Subject 2 Marks: " +mark2);
        System.out.println("Subject 3 Marks: " +mark3);
    }
}

public class Main
{
   public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        float m1,m2,m3;
        StudentMarks s1 = new StudentMarks();
        System.out.println("Enter Student Name: ");
        String name=sc.nextLine();
        s1.setName(name);
        System.out.println("Enter Student ID: ");
        int id=sc.nextInt();
        s1.setID(id);
        System.out.println("Enter Student Marks in 3 subjects: ");
        m1=sc.nextFloat();
        m2=sc.nextFloat();
        m3=sc.nextFloat();
        while(m1<0 || m1>100 || m2<0 || m2>100 || m3<0 || m3>100){ // if marj=ks is less than 0 or greater than 100, it has to be renered
            System.out.println("Enter valid marks!!!");
            m1=sc.nextFloat();
            m2=sc.nextFloat();
            m3=sc.nextFloat();
        }
        s1.setMarks(m1,m2,m3);
        s1.getDetails();
        float total= s1.total();
        System.out.println("Total marks = " + total + "/300");
        float avg = s1.average();
        System.out.println("Average marks = " + avg);
        s1.grade();
        s1.results();
   }
}

Output: