From e467a9cdde701760acb4102bc9954f04933f5c2f Mon Sep 17 00:00:00 2001
From: xuxin <840198532@qq.com>
Date: Wed, 14 Oct 2026 10:19:31 +0800
Subject: [PATCH] =?UTF-8?q?s-day02--=E6=B3=9B=E5=9E=8B=E7=9A=84=E9=80=9A?=
 =?UTF-8?q?=E9=85=8D=E7=AC=A6=E5=8F=8A=E5=85=B6=E4=B8=8A=E4=B8=8B=E9=99=90?=
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Content-Type: text/plain; charset=UTF-8
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---
 .../com/inmind/generic_common05/Demo08.java   | 42 +++++++++++++++++++
 .../com/inmind/generic_common05/Person.java   | 11 +++++
 .../com/inmind/generic_common05/Student.java  |  7 ++++
 3 files changed, 60 insertions(+)
 create mode 100644 s-day02/src/com/inmind/generic_common05/Demo08.java
 create mode 100644 s-day02/src/com/inmind/generic_common05/Person.java
 create mode 100644 s-day02/src/com/inmind/generic_common05/Student.java

diff --git a/s-day02/src/com/inmind/generic_common05/Demo08.java b/s-day02/src/com/inmind/generic_common05/Demo08.java
new file mode 100644
index 0000000..dacfef9
--- /dev/null
+++ b/s-day02/src/com/inmind/generic_common05/Demo08.java
@@ -0,0 +1,42 @@
+package com.inmind.generic_common05;
+
+import java.util.ArrayList;
+
+/*
+    13.泛型通配符的使用(了解)
+    当我们想接收一个数据类型，它们的泛型不一致，但是方法中的操作是一致的时候，如果操作？？？？
+    泛型通配符:?,它的作用是能够匹配任意的泛型类型,?使用时默认解析为Object
+
+
+    使用了通配符，还能限制传入的类型？
+    可以，受限泛型
+
+    格式:
+    <? extends B> :泛型的类型只能是B类型或者B类型的子类；上限
+    <? super B> :  泛型的类型只能是B类型或者B类型的父类；下限
+ */
+public class Demo08 {
+    public static void main(String[] args) {
+        //创建2个集合对集合的内容进行遍历打印输出
+        ArrayList<Person> list1 = new ArrayList<>();
+        list1.add(new Person("张三1", 19));
+        list1.add(new Person("张三2", 18));
+        list1.add(new Person("张三3", 17));
+
+        showList(list1);
+
+        ArrayList<Student> list2 = new ArrayList<>();
+        list2.add(new Student("张三4", 19));
+        list2.add(new Student("张三5", 18));
+        list2.add(new Student("张三6", 17));
+        showList(list2);
+    }
+
+    //定义一个接收集合，对集合进行编译输出的方法
+    public static void showList(ArrayList<? extends Person> list){//泛型的上限
+//    public static void showList(ArrayList<? super Person> list){//泛型的下限
+        for (Person p : list) {
+            System.out.println(p);
+        }
+    }
+}
diff --git a/s-day02/src/com/inmind/generic_common05/Person.java b/s-day02/src/com/inmind/generic_common05/Person.java
new file mode 100644
index 0000000..890c41a
--- /dev/null
+++ b/s-day02/src/com/inmind/generic_common05/Person.java
@@ -0,0 +1,11 @@
+package com.inmind.generic_common05;
+
+public class Person {
+    String name;
+    int age;
+
+    public Person(String name, int age) {
+        this.name = name;
+        this.age = age;
+    }
+}
diff --git a/s-day02/src/com/inmind/generic_common05/Student.java b/s-day02/src/com/inmind/generic_common05/Student.java
new file mode 100644
index 0000000..513626b
--- /dev/null
+++ b/s-day02/src/com/inmind/generic_common05/Student.java
@@ -0,0 +1,7 @@
+package com.inmind.generic_common05;
+
+public class Student extends Person{
+    public Student(String name, int age) {
+        super(name, age);
+    }
+}