package cn.sdut.lah;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;

import java.util.Map.Entry;

import java.util.Set;

import org.junit.After;

import org.junit.Before;

import org.junit.Test;

public class Demo2 {

	Map map = null;

	@Before

	public void before(){

	    map = new HashMap();//若要按照存入的顺序输出，则使用linkedHashMap

		map.put(1, "唐僧");

		map.put(2, "猪八戒");

		map.put(3, "孙悟空");

	}

	/**

	 * way1: 先获取键集合，由键的到值

	 */

	@Test

	public void test1(){

		//使用迭代器遍历

		Set set = map.keySet();

		Iterator it = set.iterator();

		while(it.hasNext()){

			int key = (int) it.next();

			String value = (String) map.get(key);

			System.out.println(key+": "+value);

		}

	}

	@Test

	public void test11(){

		//使用增强for循环遍历

		for (Object obj:map.keySet()){

			 int key = (int) obj;

			 String value = (String) map.get(key);

			 System.out.println(key+": "+value);

		 }

	}

	/**

	 * way2:先获取键值对集合，从而得到键和值

	 */

	@Test

	public void test2(){

		//使用迭代器遍历

		Set set = map.entrySet();

		Iterator it = set.iterator();

	    while(it.hasNext()){

	    	Map.Entry entry = (Entry) it.next();

	    	int key = (int) entry.getKey();

	    	String value = (String) entry.getValue();

	    	System.out.println(key+": "+value);

	    }

	}

	public void test22(){

		//使用增强for循环遍历

		for (Object obj:map.entrySet()){

			Map.Entry entry = (Entry) obj;

			int key =  (int) entry.getKey();

			String value = (String) entry.getValue();

			System.out.println(key+": "+value);

		}

	}

	@After

	public void after(){

		map = null;

	}

}