From 9f74cb1caee25859faf261be4195e751d99308a3 Mon Sep 17 00:00:00 2001
From: xuxin <840198532@qq.com>
Date: Sun, 2 Aug 2026 11:53:48 +0800
Subject: [PATCH] =?UTF-8?q?s-day02-HashSet=E5=AD=98=E5=82=A8=E8=87=AA?=
 =?UTF-8?q?=E5=AE=9A=E4=B9=89=E5=AF=B9=E8=B1=A1?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../src/com/inmind/set02/HashSetTest10.java   | 26 +++++++++++++++++++
 .../src/com/inmind/set02/HashTableDemo09.java |  8 +++---
 s-day03/src/com/inmind/set02/Student.java     |  8 ++++++
 3 files changed, 38 insertions(+), 4 deletions(-)
 create mode 100644 s-day03/src/com/inmind/set02/HashSetTest10.java

diff --git a/s-day03/src/com/inmind/set02/HashSetTest10.java b/s-day03/src/com/inmind/set02/HashSetTest10.java
new file mode 100644
index 0000000..4adf863
--- /dev/null
+++ b/s-day03/src/com/inmind/set02/HashSetTest10.java
@@ -0,0 +1,26 @@
+package com.inmind.set02;
+
+import java.util.HashSet;
+
+/*
+总结：哈希表通过对象的hashCode和equals方法来实现去重功能的，它能够在实现去重的基础上，还能保证高效查询操作
+如何保证高效，假设有1万条数据，遍历是否包含某个数据，由hashCode值，就排除了8000条数据，只要查询2000条
+
+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 HashSetTest10 {
+    public static void main(String[] args) {
+        //创建HashSet集合，保存学生对象
+        HashSet<Student> students = new HashSet<>();
+
+        //去重功能，需要将同名同年龄的学生看作是同一个学生
+        students.add(new Student("张三", 18));
+        students.add(new Student("张三", 18));
+        students.add(new Student("张三3", 18));
+        students.add(new Student("张三4", 18));
+        System.out.println(students.size());
+        System.out.println(students);
+    }
+}
diff --git a/s-day03/src/com/inmind/set02/HashTableDemo09.java b/s-day03/src/com/inmind/set02/HashTableDemo09.java
index 113dee6..d761b4c 100644
--- a/s-day03/src/com/inmind/set02/HashTableDemo09.java
+++ b/s-day03/src/com/inmind/set02/HashTableDemo09.java
@@ -17,10 +17,10 @@ public class HashTableDemo09 {
         String str3 = "通话";
         String str4 = "重地";
         //查看他们各自的哈希值
-        System.out.println(str1.hashCode());
-        System.out.println(str2.hashCode());
-        System.out.println(str3.hashCode());
-        System.out.println(str4.hashCode());
+        System.out.println(str1.hashCode());//96354
+        System.out.println(str2.hashCode());//96354
+        System.out.println(str3.hashCode());//1179395
+        System.out.println(str4.hashCode());//1179395
 
         //存入set集合
         HashSet<String> sets = new HashSet<>();
diff --git a/s-day03/src/com/inmind/set02/Student.java b/s-day03/src/com/inmind/set02/Student.java
index 75fd506..89a3279 100644
--- a/s-day03/src/com/inmind/set02/Student.java
+++ b/s-day03/src/com/inmind/set02/Student.java
@@ -26,4 +26,12 @@ public class Student extends Object {
         result = 31 * result + age;
         return result;
     }
+
+    @Override
+    public String toString() {
+        return "Student{" +
+                "name='" + name + '\'' +
+                ", age=" + age +
+                '}';
+    }
 }