test.java

import java.util.Arrays;
import java.util.*;

class Marksheet {
    int roll_no, total;
    String name;

    public void set_roll(int roll_number) {
        roll_no = roll_number;
    }

    public void set_total(int tot) {
        total = tot;
    }

    public void display() {
        System.out.println(roll_no + "\t" + total);
    }

	public static void main(String[] args) {
	    Marksheet m[] = new Marksheet[6];
	
	    m[0] = new Marksheet();
	    m[0].set_roll(1);
	    m[0].set_total(10);
	
	    m[1] = new Marksheet();
	    m[1].set_roll(2);
	    m[1].set_total(20);
	
	    m[2] = new Marksheet();
	    m[2].set_roll(3);
	    m[2].set_total(15);
	
	    m[3] = new Marksheet();
	    m[3].set_roll(4);
	    m[3].set_total(18);
	    
	    m[0].display();
	    m[1].display();
	    m[2].display();
	    m[3].display();
	    
	    Arrays.sort(m, new Comparator<Marksheet>() {
	        @Override
	        public int compare(Marksheet m1, Marksheet m2) {
	            return -1;
	        }
	    });
	    
	    m[0].display();
	    m[1].display();
	    m[2].display();
	    m[3].display();
	}
}