From b4af8373bc0e055196dab9e5ae3dfa6098c9011f Mon Sep 17 00:00:00 2001
From: xuxin <840198532@qq.com>
Date: Sun, 1 Feb 2026 14:10:36 +0800
Subject: [PATCH] =?UTF-8?q?=E8=BF=9B=E9=98=B6day03-Collections=E4=B8=AD?=
 =?UTF-8?q?=E7=9A=84addAll=E5=92=8Cshuffle=E6=96=B9=E6=B3=95?=
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---
 .../src/com/inmind/collections04/Demo13.java  | 40 +++++++++++++++++++
 1 file changed, 40 insertions(+)
 create mode 100644 javaSE-day03/src/com/inmind/collections04/Demo13.java

diff --git a/javaSE-day03/src/com/inmind/collections04/Demo13.java b/javaSE-day03/src/com/inmind/collections04/Demo13.java
new file mode 100644
index 0000000..64e3640
--- /dev/null
+++ b/javaSE-day03/src/com/inmind/collections04/Demo13.java
@@ -0,0 +1,40 @@
+package com.inmind.collections04;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+
+/*
+- java.utils.Collections是集合工具类，用来对集合进行操作。部分方法如下：
+
+- public static <T> boolean addAll(Collection<T> c, T... elements):往集合中添加一些元素。
+- public static void shuffle(List<?> list) 打乱顺序:打乱集合顺序。
+
+
+- public static <T> void sort(List<T> list):将集合中元素按照默认规则排序。
+- public static <T> void sort(List<T> list，Comparator<? super T> ):将集合中元素按照指定规则排序。
+
+ */
+public class Demo13 {
+    public static void main(String[] args) {
+        //public static <T> boolean addAll(Collection<T> c, T... elements):往集合中添加一些元素。
+        Collection<String> lists = new ArrayList<>();
+        lists.add("关羽");
+        lists.add("刘备");
+        lists.add("张飞");
+
+        System.out.println(lists);
+        System.out.println(Collections.addAll(lists, "张三", "张三1", "张三2"));
+        System.out.println(lists);
+        System.out.println("--------------------------------------------");
+        //- public static void shuffle(List<?> list) 打乱顺序:打乱集合顺序。
+        ArrayList<String> lists1 = new ArrayList<>();
+        lists1.add("关羽");
+        lists1.add("刘备");
+        lists1.add("张飞");
+        System.out.println(lists1);
+        Collections.shuffle(lists1);
+        System.out.println(lists1);
+    }
+}