package chapter07;

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

public class Test2 {
	public static void main(String[] args) {
		
		Map<String,String> map = new HashMap<String,String>();
		map.put("1", "value");
		map.put("2", "value2");
		map.put("3", "value3");
		
		//第一種：普遍使用，二次取值
		System.out.println("通過Map.keySet遍歷key和value： ");
		for(String key : map.keySet()) {
			System.out.println("key= " + key + " and value= " + map.get(key));
		}
		
		//第二種
		System.out.println("通過Map.entrySet使用iterator遍歷key和value：");
		Iterator<Map.Entry<String,String>> it = map.entrySet().iterator();
		while(it.hasNext()) {
			Map.Entry<String, String> entry = it.next();
			System.out.println("key= " + entry.getKey() + " and value= " + entry.getValue());
		}
		
		//第三種：推薦
		System.out.println("通過Map.entrySet遍歷key和value");
		for(Map.Entry<String, String> entry : map.entrySet()) {
			System.out.println("key= " + entry.getKey() + " and value= " + entry.getValue());
		}
		
		//第四重
		System.out.println("通過Map.value()遍歷所有的value,但是不能遍歷key");
		for(String v : map.values()) {
			System.out.println("value= " + v);
		}
		
	}

}