进阶day04-LinkedHashMap的特点

javaSE-day04/src/com/inmind/map01/LinkedHashMapDemo05.java

@@ -0,0 +1,49 @@
+package com.inmind.map01;
+
+import java.util.HashMap;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Set;
+
+/*
+HashMap的特点:
+1.存取无序
+2.没有索引
+3.不能重复
+
+LinkedHashMap的特点
+    hash:哈希表,它的作用是去重
+    Link:链表,它的作用保存顺序
+
+    LinkedHashMap:存储有序,没有索引,不能重复，跟LinkedHashSet是类似的
+ */
+public class LinkedHashMapDemo05 {
+    public static void main(String[] args) {
+
+        HashMap<Student, String> map = new HashMap<>();
+
+        map.put(new Student("张三", 18), "苏州");
+        map.put(new Student("李四", 19), "无锡");
+        map.put(new Student("王五", 20), "常州");
+
+        //键找值的方法遍历
+        Set<Student> keys = map.keySet();
+        for (Student key : keys) {
+            System.out.println(key+"-"+map.get(key));
+        }
+        System.out.println("-------------------------");
+
+        LinkedHashMap<Student, String> linkedmap = new LinkedHashMap<>();
+
+        linkedmap.put(new Student("张三", 18), "苏州");
+        linkedmap.put(new Student("李四", 19), "无锡");
+        linkedmap.put(new Student("王五", 20), "常州");
+
+        //键值对遍历
+        Set<Map.Entry<Student, String>> entries = linkedmap.entrySet();
+        for (Map.Entry<Student, String> entry : entries) {
+            System.out.println(entry.getKey()+":"+entry.getValue());
+        }
+
+    }
+}