diff --git "a/42\351\231\210\344\275\263\344\274\246/20230522\344\275\234\344\270\232.md" "b/42\351\231\210\344\275\263\344\274\246/20230522\344\275\234\344\270\232.md"
new file mode 100644
index 0000000000000000000000000000000000000000..b711d0a3fa526c9a494282908753645880b7aaf1
--- /dev/null
+++ "b/42\351\231\210\344\275\263\344\274\246/20230522\344\275\234\344\270\232.md"
@@ -0,0 +1,64 @@
+
+```c#
+/// <summary>
+///  筛选偶数，并从小到大排序
+/// </summary>
+
+var arr=new int[]{1,4,5,10,5};
+
+//linq表达式
+
+var arr1=from s in arr where s % 2==0 orderby s ascending select s;
+
+//链式写法
+
+var arr2=arr.Where(x=>x%2==0).OrderBy(x=>x);
+
+//遍历输出
+foreach (var item in arr1)
+{
+    Console.WriteLine(item);   
+}
+
+foreach (var item in arr2)
+{
+    Console.WriteLine(item);   
+}
+```
+![show](https://gitee.com/Cchen-jialun/picture/raw/master/20230524/zIXBw4acbAGL.png)
+
+
+```c#
+/// <summary>
+///  统计随机数出现的次数。
+/// </summary>
+
+var random = new Random();
+var arr = new int[100];
+
+for (int i = 0; i < arr.Length; i++)
+{
+    arr[i] = random.Next(100);
+}
+//定义字典存储键以及值
+var dictionary = new Dictionary<int, int>();
+
+//遍历存储键值
+foreach (var a in arr)
+{
+    if (!dictionary.ContainsKey(a))
+    {
+        dictionary[a] = 1;
+    }
+    else
+    {
+        dictionary[a]++;
+    }
+}
+//遍历输出
+foreach (var i in dictionary)
+{
+    Console.WriteLine(i);
+}
+```
+![show](https://gitee.com/Cchen-jialun/picture/raw/master/20230524/JM5RmkZKTpQK.png)
\ No newline at end of file
diff --git "a/42\351\231\210\344\275\263\344\274\246/20230523\344\275\234\344\270\232.md" "b/42\351\231\210\344\275\263\344\274\246/20230523\344\275\234\344\270\232.md"
new file mode 100644
index 0000000000000000000000000000000000000000..1d5fbb791cc74af4593949bc17853d0b22372982
--- /dev/null
+++ "b/42\351\231\210\344\275\263\344\274\246/20230523\344\275\234\344\270\232.md"
@@ -0,0 +1,53 @@
+```c#
+/// <summary>
+///  统计每个字符出现的次数 
+/// </summary>
+
+var strings = new String[] { "apple", "orange", "banner" };
+
+//linq表达式写法
+var array = from s in strings from i in s group i by i into g orderby g.Count() descending select new { g.Key, count = g.Count() };
+
+//链式写法
+var array2 = strings.SelectMany(s => s).GroupBy(x => x).OrderByDescending(g => g.Count()).Select(g => new { g.Key, count = g.Count() });
+
+//遍历输出
+foreach (var i in array)
+{
+    Console.WriteLine($"{i.Key}:{i.count}");
+}
+
+Console.WriteLine("====================================================================================");
+
+foreach (var i in array2)
+{
+    Console.WriteLine($"{i.Key}:{i.count}");
+}
+```
+![show](https://gitee.com/Cchen-jialun/picture/raw/master/20230524/!v@ok6m5P4wt.png)
+
+```c#
+/// <summary>
+///  使用AsParallel模拟同步下载三张图片
+//结果:
+/*
+	pic1 下载完成
+	pic3 下载完成
+	pic2 下载完成
+*/
+/// </summary>
+
+string pic1 = "4b069d702e7fec0dc06cf5815ece8503.jpeg";
+string pic2 = "4b069d702e7fec0dc06cf5815esn7005.jpeg";
+string pic3 = "4b069d702e7fec0dc06cf5815ets6730.jpeg";
+
+var pictures = new String[] { pic1, pic2, pic3 };
+
+
+pictures.AsParallel().ForAll(x =>
+{
+    Thread.Sleep(2000);
+    Console.WriteLine($"{x}下载完成");
+});
+```
+![show](https://gitee.com/Cchen-jialun/picture/raw/master/20230524/fvFO7*0z5Mhh.png)
\ No newline at end of file