Update string.md

docs/uts/buildin-object-api/string.md

@@ -137,17 +137,6 @@ String 全局对象是一个用于字符串或一个字符序列的构造函数
 
 <!-- UTSJSON.String.charCodeAt.compatibility -->
 
-### fromCharCode(...codes : number[]):string
-
-<!-- UTSJSON.String.fromCharCode.description -->
-
-<!-- UTSJSON.String.fromCharCode.param -->
-
-<!-- UTSJSON.String.fromCharCode.returnValue -->
-
-<!-- UTSJSON.String.fromCharCode.test -->
-
-<!-- UTSJSON.String.fromCharCode.compatibility -->
 
 
 ### concat(...strings)
@@ -695,6 +684,21 @@ let b = 2
 
 <!-- UTSJSON.String.tutorial -->
 
+## 静态方法
+
+### fromCharCode(...codes : number[]):string
+
+<!-- UTSJSON.String.fromCharCode.description -->
+
+<!-- UTSJSON.String.fromCharCode.param -->
+
+<!-- UTSJSON.String.fromCharCode.returnValue -->
+
+<!-- UTSJSON.String.fromCharCode.test -->
+
+<!-- UTSJSON.String.fromCharCode.compatibility -->
+
+
 ## Android 平台实现
 
 * 目前 string 类型编译到 kotlin 为 kotlin.String