From 0426ae9c8326b94d02714235f3c30cd3e3cce449 Mon Sep 17 00:00:00 2001
From: xuxin <840198532@qq.com>
Date: Sun, 1 Feb 2026 11:57:31 +0800
Subject: [PATCH] =?UTF-8?q?=E8=BF=9B=E9=98=B6day03-HashSet=E5=AD=98?=
 =?UTF-8?q?=E5=82=A8=E8=87=AA=E5=AE=9A=E4=B9=89=E5=AF=B9=E8=B1=A1=EF=BC=88?=
 =?UTF-8?q?=E5=BF=85=E5=AE=9A=E9=87=8D=E5=86=99hashCode&equasl=E6=96=B9?=
 =?UTF-8?q?=E6=B3=95=EF=BC=89?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../src/com/inmind/set02/HashSetDemo10.java   | 27 +++++++++++++++++++
 .../src/com/inmind/set02/Student.java         | 13 +++++++--
 2 files changed, 38 insertions(+), 2 deletions(-)
 create mode 100644 javaSE-day03/src/com/inmind/set02/HashSetDemo10.java

diff --git a/javaSE-day03/src/com/inmind/set02/HashSetDemo10.java b/javaSE-day03/src/com/inmind/set02/HashSetDemo10.java
new file mode 100644
index 0000000..e8c8d93
--- /dev/null
+++ b/javaSE-day03/src/com/inmind/set02/HashSetDemo10.java
@@ -0,0 +1,27 @@
+package com.inmind.set02;
+
+import java.util.HashSet;
+
+/*
+    HashSet存储自定义对象
+
+注意：我们保存数据时，先判断哈希值，如果不一样直接存，如果哈希值相同，还会判断equals方法。
+总结:使用HashSet要实现自定义对象的去重,必须重写hashcode和equals,原因底层是哈希表
+
+ */
+public class HashSetDemo10 {
+    public static void main(String[] args) {
+        //保存几个自定义学生对象，实现去重的效果
+        HashSet<Student> students = new HashSet<>();
+        Student s1 = new Student("刘备", 20);
+        Student s2 = new Student("关羽", 19);
+        Student s3 = new Student("张飞", 18);
+        Student s4 = new Student("张飞", 18);
+
+        students.add(s1);
+        students.add(s2);
+        students.add(s3);
+        students.add(s4);
+        System.out.println(students);
+    }
+}
diff --git a/javaSE-day03/src/com/inmind/set02/Student.java b/javaSE-day03/src/com/inmind/set02/Student.java
index dcb1a2c..309ba5e 100644
--- a/javaSE-day03/src/com/inmind/set02/Student.java
+++ b/javaSE-day03/src/com/inmind/set02/Student.java
@@ -10,8 +10,8 @@ public class Student {
         this.name = name;
         this.age = age;
     }
-
-
+    //如果没有重写equals方法，默认使用==比较地址来判断是否相同
+    //已经重写了equals方法，比较属性的内容
     @Override
     public boolean equals(Object o) {
         if (o == null || getClass() != o.getClass()) return false;
@@ -20,10 +20,19 @@ public class Student {
         return age == student.age && name.equals(student.name);
     }
 
+    //当前学生类的哈希值，跟内容有关，属性相同的学生对象的哈希值必定相同
     @Override
     public int hashCode() {
         int result = name.hashCode();
         result = 31 * result + age;
         return result;
     }
+
+    @Override
+    public String toString() {
+        return "Student{" +
+                "name='" + name + '\'' +
+                ", age=" + age +
+                '}';
+    }
 }