diff --git a/Software/Development/Library/C_Standard_Library/C_标准输入输出及格式化说明.md b/Software/Development/Library/C_Standard_Library/C_标准输入输出及格式化说明.md
index c46d442..fded66a 100644
--- a/Software/Development/Library/C_Standard_Library/C_标准输入输出及格式化说明.md
+++ b/Software/Development/Library/C_Standard_Library/C_标准输入输出及格式化说明.md
@@ -72,3 +72,13 @@
 | \r      | 回车 |
 | \t      | 水平制表符 |
 | \v      | 垂直制表符 |
+
+## 示例
+
+```cpp
+int a=0x10A;
+printf("%x.\n", a);     // print 10a.
+printf("%#x.\n", a);    // print 0x10a.
+printf("%X.\n", a);     // print 10A
+printf("%#X.\n", a);    // print 0X10A
+```