package cn.burce.HashMap;

import java.util.HashMap;

public class MapDemo3 {
    // 神奇小學
    // 一年級
    // 101 小米 102 小明
    // 二年級
    // 201 大米 202 大明
    public static void main(String[] args) {
        fun();
        System.out.println("----------------------------------");
        fun1();
    }

    public static
 
 void fun() {
        HashMap<String, String> one = new HashMap<>();
        HashMap<String, String> two = new HashMap<>();
        one.put("101", "小米");
        one.put("102", "小明");
        two.put("201", "大米");
        two.put("202", "大明");
        HashMap<String, HashMap<String, String>> school = new
 
 HashMap<>();
        school.put("一年級", one);
        school.put("二年級", two);
        System.out.println(school + "大大主鍵");
        Set<String> set = new HashSet<>();
        set = school.keySet();// 將鍵存到set集合，鍵是一個String
        Iterator<String> it = set.iterator();// 通過Iterator去遍歷這組字串
 

        while (it.hasNext())
        {
            String str = it.next();
            System.out.println(str + "大主鍵");
            HashMap<String, String> p1 = school.get(str);
            System.out.println(p1 + "巢狀集合");
            Set<String> set1 = p1.keySet();// 將鍵存到set集合，鍵是一個String
            System.out.println("set1是"+set1);
            // 增強for
            for (String s : set1)
            {
                System.out.println(str+"..."+s+"..."+p1.get(s));
            }
        }
    }

    public static void fun1() {
        HashMap<String, String> thr = new HashMap<>();
        HashMap<String, String> four = new HashMap<>();
        thr.put("301", "豪情天下");
        thr.put("302", "光陰似箭");
        four.put("401", "龍騰萬里");
        four.put("402", "無印之水");
        HashMap<String, HashMap<String, String>> school = new HashMap<>();
        school.put("三年級", thr);
        school.put("四年級", four);
        System.out.println(school + "大大主鍵");
        // 將map中的方法 entrySet取出對映關係，存到Set集合裡Set<K,V>
        Set<Map.Entry<String, HashMap<String, String>>> set = school.entrySet();
        Iterator<Map.Entry<String, HashMap<String, String>>> it = set.iterator();
        while (it.hasNext())
        {// 獲取出set集合的元素，這裡仍舊是map結構
            Map.Entry<String, HashMap<String, String>> entry = it.next();
            // 根據getKey和getValue取出鍵值
            String s = entry.getKey();
            // System.out.println(s);
            HashMap<String, String> zclass = entry.getValue();
            Set<Map.Entry<String, String>> set1 = zclass.entrySet();
            // 增強for
            for (Map.Entry<String, String> entry2 : set1)
            {
                System.out.println(s + "..." + entry2.getKey() + "..." + entry2.getValue());
            }
        }
    }
}

實際上也就是多重的集合取數