添加Lesson2

C#进阶/C#进阶.sln

@@ -9,6 +9,10 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lesson1_ArrayList", "Lesson
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lesson1_ArrayList练习题", "Lesson1_ArrayList练习题\Lesson1_ArrayList练习题.csproj", "{B9F9E174-21EA-40E7-A139-58FFD3448023}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lesson2_Stack", "Lesson2_Stack\Lesson2_Stack.csproj", "{8353E167-0804-4902-A15A-3FA209EB6C6E}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lesson2_Stack练习题", "Lesson2_Stack练习题\Lesson2_Stack练习题.csproj", "{BE917425-E4A8-4C51-89BE-8F6DD86A1C00}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -27,6 +31,14 @@ Global
 		{B9F9E174-21EA-40E7-A139-58FFD3448023}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{B9F9E174-21EA-40E7-A139-58FFD3448023}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{B9F9E174-21EA-40E7-A139-58FFD3448023}.Release|Any CPU.Build.0 = Release|Any CPU
+		{8353E167-0804-4902-A15A-3FA209EB6C6E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{8353E167-0804-4902-A15A-3FA209EB6C6E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{8353E167-0804-4902-A15A-3FA209EB6C6E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{8353E167-0804-4902-A15A-3FA209EB6C6E}.Release|Any CPU.Build.0 = Release|Any CPU
+		{BE917425-E4A8-4C51-89BE-8F6DD86A1C00}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{BE917425-E4A8-4C51-89BE-8F6DD86A1C00}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{BE917425-E4A8-4C51-89BE-8F6DD86A1C00}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{BE917425-E4A8-4C51-89BE-8F6DD86A1C00}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

C#进阶/Lesson2_Stack/Lesson2_Stack.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

C#进阶/Lesson2_Stack/Program.cs

@@ -0,0 +1,109 @@
+using System.Collections;
+namespace Lesson2_Stack
+{
+    class Test()
+    {
+
+    }
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            #region 知识点一 Stack本质
+            //stack是C#是为我们封装好的类
+            //本质是一个Object数组，只是封装了特殊的存储规则
+
+            //stack是栈存储容器，栈是一种先进后出的数据结构
+            //先存入的数据后取出，后存入的数据先取出
+            //栈的存储规则：后进先出
+            #endregion
+
+            #region 知识点二 声明
+            //需要引用命名空间system.collections
+            Stack stack = new Stack();
+            #endregion
+
+            #region 知识点三 增取查改
+
+            #region 增
+            //压栈
+            stack.Push(1);
+            stack.Push("123");
+            stack.Push(true);
+            stack.Push(3.14f);
+            stack.Push(new Test());
+            #endregion
+
+            #region 取
+            //栈中不存在删除的概念
+            //只能取出栈顶的数据
+            //弹栈
+            object v = stack.Pop();//弹出栈顶元素，下次弹出的是下一个元素
+            Console.WriteLine(v);
+            v = stack.Pop();
+            Console.WriteLine(v);
+            #endregion
+
+            #region 查
+            //栈无法查看指定位置的元素,栈没有提供索引器
+            //只能查看栈顶的元素
+            v = stack.Peek();//只看不弹出
+            Console.WriteLine(v);
+            v = stack.Peek();
+            Console.WriteLine(v);
+
+            //查看元素是否存在于栈中
+            if (stack.Contains(3.14f))
+            {
+                Console.WriteLine("存在3.14");
+            }
+            if (stack.Contains("123"))
+            {
+                Console.WriteLine("存在123");
+            }
+            #endregion
+
+            #region 改
+            //栈无法修改指定位置的元素
+            //只能修改栈顶的元素或清空
+            stack.Clear();//清空栈
+            stack.Push("1");
+            stack.Push(2);
+            stack.Push("gfjd");
+            #endregion
+            #endregion
+
+            #region 知识点四 遍历
+            //1.长度
+            Console.WriteLine(stack.Count);
+
+            //2.遍历
+            foreach(Object o in stack)
+            {
+                Console.WriteLine(o);
+            }
+
+            //3.还有一种遍历方式
+            //先将栈转换为数组
+            //注意转换后的数组是倒序的
+            object[] arr = stack.ToArray();
+            for(int i = 0;i < arr.Length; i++)
+            {
+                Console.WriteLine(arr[i]);
+            }
+
+            //4.循环弹栈
+            while(stack.Count > 0)
+            {
+                Console.WriteLine(stack.Pop());
+            }
+            #endregion
+
+            #region 知识点五 
+            //由于用object来存储数据，所以存储值类型时会装箱，取出时需要拆箱
+            //Push值类型时装箱
+            //弹出时拆箱
+            #endregion
+        }
+    }
+}

C#进阶/Lesson2_Stack练习题/Lesson2_Stack练习题.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

C#进阶/Lesson2_Stack练习题/Program.cs

@@ -0,0 +1,24 @@
+using System.Collections;
+namespace Lesson2_Stack练习题
+{
+    internal class Program
+    {
+        static void Main(string[] args)
+        {
+            Console.Write("输入一个数字:");
+            int num = int.Parse(Console.ReadLine());
+            Stack bio = new Stack();
+            while (num != 0)
+            {
+                int r = num % 2;
+                bio.Push(r);
+                num /= 2;
+            }
+            Console.Write("你输入的数字二进制为:");
+            while (bio.Count > 0)
+            {
+                Console.Write(bio.Pop());
+            }
+        }
+    }
+}