17-5:LinkedHashSet有序且为链表，HashSet无序

package cn.itcast.p4.hashset.demo;

import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;

public class LinkedHashSetDemo {

	/**
	 * @param args
	 */
	public static void main(String[] args) {

		HashSet hs = new LinkedHashSet();
		
		hs.add("hahah");
		hs.add("hehe");
		hs.add("heihei");
		hs.add("xixii");
//		hs.add("hehe");
		
		Iterator it = hs.iterator();
		
		while(it.hasNext()){
			System.out.println(it.next());
		}
	}

}

package cn.itcast.p4.hashset.demo;

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

public class HashSetDemo {

	/**
	 * @param args
	 */
	public static void main(String[] args) {

		HashSet hs = new HashSet();
		
		hs.add("hehe");
//		hs.add("heihei");
		hs.add("hahah");
		hs.add("xixii");
		hs.add("hehe");
		
		Iterator it = hs.iterator();
		
		while(it.hasNext()){
			System.out.println(it.next());
		}
	}

}

package cn.itcast.p4.hashset.test;

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

import cn.itcast.p.bean.Person;

public class HashSetTest {

	/**
	 * @param args
	 */
	public static void main(String[] args) {

		
		HashSet hs = new HashSet();

		
		hs.add(new Person("lisi4",24));
		hs.add(new Person("lisi7",27));
		hs.add(new Person("lisi1",21));
		hs.add(new Person("lisi9",29));
		hs.add(new Person("lisi7",27));
		
		
		Iterator it = hs.iterator();
		
		while(it.hasNext()){
			Person p = (Person)it.next();
			System.out.println(p);
//			System.out.println(p.getName()+"...."+p.getAge());
		}
	}

}