diff --git "a/21\350\242\201\345\251\247\346\226\207" "b/21\350\242\201\345\251\247\346\226\207"
new file mode 100644
index 0000000000000000000000000000000000000000..8450a64f5e7dd907859c751d488276917031495c
--- /dev/null
+++ "b/21\350\242\201\345\251\247\346\226\207"
@@ -0,0 +1,29 @@
+using System;
+class Program
+{
+    static void Main()
+    {
+        // 基本方法：使用临时变量
+        int n1 = 10, n2 = 20;
+        int temp = n1;
+        n1 = n2;
+        n2 = temp;
+        Console.WriteLine($"基本方法：n1={n1}, n2={n2}"); // 输出：n1=20, n2=10
+
+        // 扩展方法1：算术运算（加减法）
+        n1 = 10;
+        n2 = 20;
+        n1 = n1 + n2;   // n1 = 30 (10+20)
+        n2 = n1 - n2;   // n2 = 10 (30-20)
+        n1 = n1 - n2;   // n1 = 20 (30-10)
+        Console.WriteLine($"算术交换：n1={n1}, n2={n2}"); // 输出：n1=20, n2=10
+
+        // 扩展方法2：位运算（异或操作）
+        n1 = 10;
+        n2 = 20;
+        n1 = n1 ^ n2;   // n1 = 10 ^ 20 = 30
+        n2 = n1 ^ n2;   // n2 = 30 ^ 20 = 10
+        n1 = n1 ^ n2;   // n1 = 30 ^ 10 = 20
+        Console.WriteLine($"异或交换：n1={n1}, n2={n2}"); // 输出：n1=20, n2=10
+    }
+}
\ No newline at end of file