From 02711c6ae36017824f045b0279156e741bea3f87 Mon Sep 17 00:00:00 2001
From: xuxin <840198532@qq.com>
Date: Mon, 3 Aug 2026 09:43:47 +0800
Subject: [PATCH] =?UTF-8?q?s-day04-Map=E9=9B=86=E5=90=88=E7=9A=84=E5=9F=BA?=
 =?UTF-8?q?Map=E9=9B=86=E5=90=88=E7=9A=84=E7=AC=AC=E4=B8=80=E7=A7=8D?=
 =?UTF-8?q?=E9=81=8D=E5=8E=86=E6=96=B9=E5=BC=8F(=E9=94=AE=E6=89=BE?=
 =?UTF-8?q?=E5=80=BC)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 s-day04/src/com/inmind/map01/MapDemo02.java | 38 +++++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 s-day04/src/com/inmind/map01/MapDemo02.java

diff --git a/s-day04/src/com/inmind/map01/MapDemo02.java b/s-day04/src/com/inmind/map01/MapDemo02.java
new file mode 100644
index 0000000..9376f9b
--- /dev/null
+++ b/s-day04/src/com/inmind/map01/MapDemo02.java
@@ -0,0 +1,38 @@
+package com.inmind.map01;
+
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Set;
+
+/*
+3.Map集合的第一种遍历方式(键找值)
+Map也是没有索引，也没有迭代器功能，所以不能通过普通for循环，也不能通过迭代器和foreach遍历，只能间接遍历
+
+- public Set<K> keySet(): 获取Map集合中所有的键，存储到Set集合中。
+ */
+public class MapDemo02 {
+    public static void main(String[] args) {
+        //创建K和V都是字符串的双列集合
+        Map<String,String> maps = new HashMap<>();
+        maps.put("刘备","孙尚香");
+        maps.put("吕布","貂蝉");
+        maps.put("张飞","夏侯驰");
+        //遍历：先获取所有的键，然后对键进行遍历（间接遍历）
+        Set<String> keys = maps.keySet();
+        //迭代器遍历
+        Iterator<String> iterator = keys.iterator();
+        while (iterator.hasNext()) {
+            String key = iterator.next();
+            String value = maps.get(key);
+            System.out.println(key + "=" + value);
+        }
+        System.out.println("--------------");
+        //foreach循环
+        for (String key : keys) {
+            String value = maps.get(key);
+            System.out.println(key + "=" + value);
+        }
+
+    }
+}