diff --git a/docs/book/13-Functional-Programming.md b/docs/book/13-Functional-Programming.md
index 86d70f08..d3ab88ac 100644
--- a/docs/book/13-Functional-Programming.md
+++ b/docs/book/13-Functional-Programming.md
@@ -97,7 +97,7 @@ public class Strategize {
 
 ```
 hello there?
-HELLO THERE!'
+HELLO THERE!
 Hello
 Hello there Hello there
 ```
@@ -1518,4 +1518,4 @@ Lambda 表达式和方法引用并没有将 Java 转换成函数式语言，而
 
 
 <!-- 分页 -->
-<div style="page-break-after: always;"></div>
\ No newline at end of file
+<div style="page-break-after: always;"></div>