fixed foreach error

data/1.Java初阶/9.控制执行流程/2.for/foreach.md

@@ -37,6 +37,7 @@ public class App {
 
 ### B
 
+```java
 public class App {
     public int words(List<String> content){
         int count = 0;
@@ -48,9 +49,11 @@ public class App {
         return count;
     }
 }
+```
 
 ### C
 
+```java
 public class App {
     public int words(List<String> content){
         int count = 0;
@@ -63,4 +66,5 @@ public class App {
         }
         return count;
     }
-}
\ No newline at end of file
+}
+```
\ No newline at end of file