ArrayList HashSet LinkedHashSet TreeSet

import java.util.*;

public class MyCollectionExample
{
public static void main(String args[])
{
ArrayList<Integer> alist = new ArrayList<Integer>();

alist.add(301); // alist.add(new Integer(301));  autoboxing  alist.add(Integer.valueOf(301));
alist.add(3425);
alist.add(123);
alist.add(4560);
alist.add(123);
alist.add(203);
alist.add(new Integer(301));

System.out.println("Array List elements : ") ;
for (int i=0; i<alist.size(); i++)
{
System.out.println(alist.get(i));
}
// Set example

HashSet<Integer> hset = new HashSet<Integer>();

hset.add(301); //   autoboxing  alist.add(Integer.valueOf(301));
hset.add(3425);
hset.add(123);
hset.add(4560);
hset.add(123);
hset.add(203);
hset.add(new Integer(301));

System.out.println("Set  elements : ") ;
//System.out.println(hset.size());
// Print elements of Set using Iterator object
// create iterator object on hashset

Iterator  myit = hset.iterator();

while ( myit.hasNext() )
System.out.println(myit.next());

// Example of LinkedHashSet  ordered collection of type set
LinkedHashSet<Integer> lhset = new LinkedHashSet<Integer>();

lhset.add(301); //  autoboxing
lhset.add(3425);
lhset.add(123);
lhset.add(4560);
lhset.add(123);
lhset.add(203);
lhset.add(new Integer(301));

System.out.println("Linked Hash Set  elements : ") ;

Iterator  lmyit = lhset.iterator();

while ( lmyit.hasNext() )
System.out.println(lmyit.next());

// Example of Tree Set  ordered collection of type set
TreeSet<Integer> tset = new TreeSet<Integer>();

/* TreeSet<Student> tstudent = new TreeSet<Student>();

Student s1 = new Student(104,"Mohin",70);
Student s2 = new Student(102,"Udit",80);

tstudent.add(s1);
tstudent.add(s2);
*/

tset.add(301); //  autoboxing
tset.add(3425);
tset.add(123);
tset.add(4560);
tset.add(123);
tset.add(203);
tset.add(new Integer(301));

System.out.println("Tree Set  elements : ") ;

Iterator  tmyit = tset.iterator();

while ( tmyit.hasNext() )
System.out.println(tmyit.next());



}
}