diff --git a/operators/transformation/switchmap.md b/operators/transformation/switchmap.md
index bea75f4..2c65cb0 100644
--- a/operators/transformation/switchmap.md
+++ b/operators/transformation/switchmap.md
@@ -42,7 +42,7 @@ import { switchMap } from 'rxjs/operators';
 const source = timer(0, 5000);
 // 当 source 发出值时切换到新的内部 observable，发出新的内部 observable 所发出的值
 const example = source.pipe(switchMap(() => interval(500)));
-// 输出: 0,1,2,3,4,5,6,7,8,9...0,1,2,3,4,5,6,7,8
+// 输出: 0,1,2,3,4,5,6,7,8,0,1,2,3,4,5,6,7,8...0,1,2,3,4,5,6,7,8
 const subscribe = example.subscribe(val => console.log(val));
 ```