diff --git a/docs/iterator.md b/docs/iterator.md
index ebe3589..db07920 100644
--- a/docs/iterator.md
+++ b/docs/iterator.md
@@ -155,6 +155,14 @@ let obj = {
 
 ```
 
+对于类似数组的对象，部署Iterator接口，有一个简便方法，就是`Symbol.iterator`方法直接引用数值的Iterator接口。
+
+```javascript
+
+NodeList.prototype[Symbol.iterator] = Array.prototype[Symbol.iterator];
+
+```
+
 如果`Symbol.iterator`方法返回的不是遍历器，解释引擎将会报错。
 
 ```javascript
diff --git a/docs/string.md b/docs/string.md
index 40d7f0a..4d878b7 100644
--- a/docs/string.md
+++ b/docs/string.md
@@ -256,8 +256,8 @@ normalize方法可以接受四个参数。
 
 ```javascript
 
-'\u004F\u030C'.normalize(NFC).length // 1
-'\u004F\u030C'.normalize(NFD).length // 2
+'\u004F\u030C'.normalize('NFC').length // 1
+'\u004F\u030C'.normalize('NFD').length // 2
 
 ```