From b7470d5c0773b0a886fc89130c4bcc28d056a6e1 Mon Sep 17 00:00:00 2001
From: xuxin <840198532@qq.com>
Date: Sun, 2 Aug 2026 10:49:28 +0800
Subject: [PATCH] =?UTF-8?q?s-day02-=E5=AF=B9=E8=B1=A1=E7=9A=84=E5=93=88?=
 =?UTF-8?q?=E5=B8=8C=E5=80=BC?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../src/com/inmind/set02/HashCodeDemo08.java  | 25 ++++++++++++++++
 .../src/com/inmind/set02/HashSetDemo07.java   |  1 +
 s-day03/src/com/inmind/set02/Student.java     | 29 +++++++++++++++++++
 3 files changed, 55 insertions(+)
 create mode 100644 s-day03/src/com/inmind/set02/HashCodeDemo08.java
 create mode 100644 s-day03/src/com/inmind/set02/Student.java

diff --git a/s-day03/src/com/inmind/set02/HashCodeDemo08.java b/s-day03/src/com/inmind/set02/HashCodeDemo08.java
new file mode 100644
index 0000000..31075ee
--- /dev/null
+++ b/s-day03/src/com/inmind/set02/HashCodeDemo08.java
@@ -0,0 +1,25 @@
+package com.inmind.set02;
+/*
+1.什么是哈希值??
+    哈希值就是一个对象的特征码,使用一个十进制int值来表示的.int的值是有限的，但是对象是无限的(不同的对象的哈希值可能相同)
+2.如何获取一个对象的哈希值呢??
+    Object类中有一个方法hashCode方法可以获取
+
+    Object类的hashCode的源码:
+    public native int hashCode();//通过真正的地址值使用哈希算法返回的一个int值
+3.我们发现每个对象的哈希值默认是通过地址来获取,这样没有意义.我们在实际开发中
+    希望拥有相同内容的同一类对象的哈希值的一致.所以子类重写hashcode.我们可以模拟一个
+    已经重写过hashcode,并且经常使用的类.得出一个结论,String的哈希值跟它的内容有关,那么
+    自定义类重写hashcode那么也应该跟类的内容(属性)有关
+ */
+public class HashCodeDemo08 {
+    public static void main(String[] args) {
+        Student s = new Student("张三", 18);
+        Student s1 = new Student("张三", 18);
+        int i = s.hashCode();
+        System.out.println(i);
+        System.out.println(s);
+        //按照我们实际开发的需求，认作是同一个对象的哈希值就应该一样！！！！
+        System.out.println(s1.hashCode());
+    }
+}
diff --git a/s-day03/src/com/inmind/set02/HashSetDemo07.java b/s-day03/src/com/inmind/set02/HashSetDemo07.java
index 24a2a46..ba77f32 100644
--- a/s-day03/src/com/inmind/set02/HashSetDemo07.java
+++ b/s-day03/src/com/inmind/set02/HashSetDemo07.java
@@ -33,5 +33,6 @@ public class HashSetDemo07 {
             System.out.println(e);
         }
 
+
     }
 }
diff --git a/s-day03/src/com/inmind/set02/Student.java b/s-day03/src/com/inmind/set02/Student.java
new file mode 100644
index 0000000..75fd506
--- /dev/null
+++ b/s-day03/src/com/inmind/set02/Student.java
@@ -0,0 +1,29 @@
+package com.inmind.set02;
+
+import java.util.Objects;
+
+public class Student extends Object {
+    String name;
+    int age;
+
+    public Student(String name, int age) {
+        this.name = name;
+        this.age = age;
+    }
+
+
+    @Override
+    public boolean equals(Object o) {
+        if (o == null || getClass() != o.getClass()) return false;
+
+        Student student = (Student) o;
+        return age == student.age && Objects.equals(name, student.name);
+    }
+
+    @Override
+    public int hashCode() {
+        int result = Objects.hashCode(name);
+        result = 31 * result + age;
+        return result;
+    }
+}