From 9a9e6a53bf635c04a54321571840d9c11c706d85 Mon Sep 17 00:00:00 2001
From: xuxin <840198532@qq.com>
Date: Sat, 16 May 2026 10:47:25 +0800
Subject: [PATCH] =?UTF-8?q?day07-=E5=B8=B8=E7=94=A8=E7=B1=BB-ArrayList-?=
 =?UTF-8?q?=E7=BB=83=E4=B9=A0?=
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---
 day07/src/com/inmind/arraylist03/Demo10.java | 21 +++++++++++
 day07/src/com/inmind/arraylist03/Demo11.java | 28 +++++++++++++++
 day07/src/com/inmind/arraylist03/Demo12.java | 37 ++++++++++++++++++++
 day07/src/com/inmind/arraylist03/Test13.java |  8 +++++
 4 files changed, 94 insertions(+)
 create mode 100644 day07/src/com/inmind/arraylist03/Demo10.java
 create mode 100644 day07/src/com/inmind/arraylist03/Demo11.java
 create mode 100644 day07/src/com/inmind/arraylist03/Demo12.java
 create mode 100644 day07/src/com/inmind/arraylist03/Test13.java

diff --git a/day07/src/com/inmind/arraylist03/Demo10.java b/day07/src/com/inmind/arraylist03/Demo10.java
new file mode 100644
index 0000000..f813071
--- /dev/null
+++ b/day07/src/com/inmind/arraylist03/Demo10.java
@@ -0,0 +1,21 @@
+package com.inmind.arraylist03;
+
+import java.util.ArrayList;
+
+//常用类_ArrayList_练习1_添加小数double
+public class Demo10 {
+    public static void main(String[] args) {
+        //创建一个存放小数的集合
+        ArrayList<Double> lists = new ArrayList<>();
+        //添加数据
+        lists.add(1.0);
+        lists.add(2.0);
+        lists.add(3.0);
+        System.out.println(lists);
+        double d = 4;//自动类型提升
+        lists.add(d);
+
+        //获取第4个值
+        System.out.println(lists.get(3));//4.0
+    }
+}
diff --git a/day07/src/com/inmind/arraylist03/Demo11.java b/day07/src/com/inmind/arraylist03/Demo11.java
new file mode 100644
index 0000000..87cd7e0
--- /dev/null
+++ b/day07/src/com/inmind/arraylist03/Demo11.java
@@ -0,0 +1,28 @@
+package com.inmind.arraylist03;
+
+import java.util.ArrayList;
+
+//常用类_ArrayList_练习2_添加对象
+public class Demo11 {
+    public static void main(String[] args) {
+        //创建一个集合，保存3个学生对象
+        ArrayList<Student> students = new ArrayList<>();
+        //创建3个学生对象
+        Student s1 = new Student("小王1", 18);
+        Student s2 = new Student("小王2", 19);
+        Student s3 = new Student("小王3", 17);
+
+        students.add(s1);
+        students.add(s2);
+        students.add(s3);
+        System.out.println(students);
+
+        //遍历集合，将每个学生的信息输出
+        for (int i = 0; i < students.size(); i++) {
+            //获取每个元素
+            Student s = students.get(i);
+            System.out.println(s.getName() + "---" + s.getAge());
+        }
+
+    }
+}
diff --git a/day07/src/com/inmind/arraylist03/Demo12.java b/day07/src/com/inmind/arraylist03/Demo12.java
new file mode 100644
index 0000000..7fb7cff
--- /dev/null
+++ b/day07/src/com/inmind/arraylist03/Demo12.java
@@ -0,0 +1,37 @@
+package com.inmind.arraylist03;
+
+import java.util.ArrayList;
+
+/*
+ArrayList_练习3_指定格式拼接字符串
+定义以指定格式打印集合的方法(ArrayList类型作为参数)，使用@分隔每个元素。
+格式参照 [元素@元素@元素]。
+ */
+public class Demo12 {
+    public static void main(String[] args) {
+        //准备好数据，调用方法即可
+        ArrayList<String> list = new ArrayList<>();
+        list.add("杨幂");
+        list.add("白鹿");
+        list.add("杨超越");
+        printArrayList(list);
+    }
+
+    //定义以指定格式打印集合的方法(ArrayList类型作为参数)
+    public static void printArrayList(ArrayList<String> list) {
+        String resutl = "[";
+        //遍历集合，获取每个元素
+        for (int i = 0; i < list.size(); i++) {
+            //获取每个元素
+            String s = list.get(i);
+            //判断是否是最后一个元素（一个集合的最后一个索引值一定是集合.size() - 1）
+            if (i == (list.size() - 1)) {
+                resutl = resutl + s + "]";
+            } else {
+                resutl = resutl + s + "@";
+            }
+        }
+
+        System.out.println(resutl);
+    }
+}
diff --git a/day07/src/com/inmind/arraylist03/Test13.java b/day07/src/com/inmind/arraylist03/Test13.java
new file mode 100644
index 0000000..88feeda
--- /dev/null
+++ b/day07/src/com/inmind/arraylist03/Test13.java
@@ -0,0 +1,8 @@
+package com.inmind.arraylist03;
+/*
+常用类_ArrayList_练习4_获取偶数集合
+有一个原本的集合，该集合中有正整数，1,3,4,5,8,9
+将集合中的偶数都取出来，保存，奇数不要
+ */
+public class Test13 {
+}