ArrayList Using class

 class Student{

int rollno;

String name;

int age;

Student(int rollno, String name, int age ){

this.rollno = rollno;

this.name = rollno;

}

}

import java.util.*;

public class ArrayListUsingClasses{

public static void main(String args[]){

//crearting user defined class object;

Student s1 = new Student(100,"Monu",32);

Student s2 = new Student(101,"Sonu",30);

Student s3 = new Student(102,"Mukka",28);

//defining an arraylist;

ArrayList<Student> arr = new ArrayList<Student>();

//adding student class object

arr.add(s1);

arr.add(s2);

arr.add(s3);

//getting iterator

Iterator itr = arr.iterator();

//traversing elements of Arraylist object;

while(itr.hasNext()){

Student st = (Student)itr.next();

System.out.println(st.rollno+" "+st.age+""+st.name);

}

}

}