package com.neuedu.list;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
/**
 * Map的三種輸出方式
 * @author geng_
 *1、toString
 *2、先把key放在set中，然後根據key找到value輸出
 *3、entrySet 效率最高，建議使用
 */
public class MAPOutputDemo {
	public static void main(String[] args) {
		HashMap hm = new HashMap();
		hm.put(1, "chen");
		hm.put(2, "chen");
		hm.put(3, "zhang");
		hm.put(4, "wang");
		hm.put(2, "sun");
		//1、
		System.out.println(hm);//預設呼叫toString
		System.out.println("\n----------------------");
		//2、
		Set keys = hm.keySet();
		for (Object key : keys) {
			System.out.print(key+"="+hm.get(key));
		}
		System.out.println("\n----------------------");
		//3\***
		Set<Map.Entry> ms =hm.entrySet();
		for (Map.Entry entry : ms) {
			System.out.print(entry.getKey()+"="+entry.getValue());
		}
		System.out.println("\n----------------------");
	}
}