package com.yds.review.list11;

import java.util.Date;
import java.util.HashSet;
import java.util.Iterator;

public class TestHashSet{
    public static void main(String[] args) {
        HashSet h = new HashSet();
        h.add("1st");
        h.add("2nd");
        h.add(new Integer(3));
        h.add(new Double(4.0));
        h.add("2nd");          // 重复元素, 未被加入
        h.add(new Integer(3));     // 重复元素,未被加入
        h.add(new Date());
        System.out.println("开始: size=" + h.size());
        Iterator it = h.iterator();
        while(it.hasNext()){
            Object o = it.next();
            System.out.println(o);    
        }
        
        h.remove("2nd");
        System.out.println("移除元素后: size=" + h.size());
        System.out.println(h);
    }
}