Contents

package lianxi;

import java.util.*;
import java.io.*;

public class lianxix {
	public static void main(String[] args) {
		HashMap<String, String> map = new HashMap<String, String>();
		map.put("yusijia", "dabai");
		map.put("wutongyu", "datong");
		map.put("tong", "bai");
		System.out.println(map);
		System.out.println("datong is in the map? " + map.containsKey("wutongyu"));
		map.remove("tong");
		System.out.println(map);
		
		//返回此映射中所包含的键的 Set 视图。
		Iterator it = map.keySet().iterator();//用迭代器遍历HashMap
		while(it.hasNext()){
			String key = (String)it.next();
			System.out.println("key: " + key);
			System.out.println("value: " + map.get(key));
			System.out.println("The hashCode of value: " + map.get(key).hashCode());
		}
		System.out.println(map.size());//返回此映射中的键-值映射关系数。
		
		//返回此映射所包含的值的 Collection 视图。
		Iterator it2 = map.values().iterator();
		while(it2.hasNext()){
			String vaule = (String)it2.next();
			System.out.println(vaule);
		}
	}
}