//HashSetDemo.java
//Illustrates the following HashSet methods:
//add()
//remove()
//contains()
//toArray()

import java.util.HashSet;

public class HashSetDemo
{
	public static void main(String[] args)
	{
		HashSet<Integer> intSet = new HashSet<Integer>();

		intSet.add(2);
		intSet.add(7);
		intSet.add(7);	// Ignored since 7 is already in the set
		intSet.add(3);
		printSet(intSet);

		intSet.remove(3);
		printSet(intSet);

		System.out.println("Set contains 2: " +
			intSet.contains(2));
		System.out.println("Set contains 3: " +
			intSet.contains(3));
	}

	public static void printSet(HashSet<Integer> intSet)
	{
		System.out.println("The set contains:");
		for (Object obj : intSet.toArray())
		{
			Integer num = (Integer) obj;
			//System.out.println(num.intValue());
			System.out.println(num);
		}
	}
}