s-day04--集合的嵌套

2026-10-15 14:41:11 +08:00
parent d69297502e
commit 6a48cf31dd
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+package com.inmind.map01;
+
+import java.util.*;
+
+/*
+    8.集合的嵌套
+    使用集合的嵌套，显示哪个省份有哪些城市
+    省份作为Key String
+    城市作为值（有很多数据，容器集合）
+ */
+public class Demo07 {
+    public static void main(String[] args) {
+        Map<String, ArrayList<String>> map = new HashMap<>();
+        ArrayList<String> jsList = new ArrayList<>();
+        Collections.addAll(jsList, "南京", "无锡", "徐州", "常州","苏州" );
+        ArrayList<String> zjList = new ArrayList<>();
+        Collections.addAll(zjList, "杭州", "宁波", "温州", "嘉兴","湖州" );
+        map.put("江苏省", jsList);
+        map.put("浙江省", zjList);
+        Set<Map.Entry<String, ArrayList<String>>> entries = map.entrySet();
+        for (Map.Entry<String, ArrayList<String>> entry : entries) {
+            System.out.println(entry.getKey()+":"+entry.getValue());
+        }
+
+    }
+}