fixed 8479f301 from https://gitee.com/wu-fengshan/docs/pulls/3739

Signed-off-by: Nwufengshan <wufengshan@huawei.com>

 Changes to be committed:

zh-cn/application-dev/reference/apis/js-apis-distributed-data.md

@@ -2263,10 +2263,10 @@ on(event: 'syncComplete', syncCallback: Callback<Array<[string, number]&gt
 
 **示例**
 
-```
+```js
 let kvStore;
 kvStore.on('syncComplete', function (data) {
-    console.log("syncComplete callback call data: " + data);
+    console.log("callback call data: " + data);
 });
 ```
 
@@ -2290,10 +2290,10 @@ off(event:'dataChange', observer?: Callback<ChangeNotification>): void
 ```js
 let kvStore;
 kvStore.on('dataChange', function (data) {
-    console.log("syncComplete callback call data: " + data);
+    console.log("callback call data: " + data);
 });
 kvStore.off('dataChange', function (data) {
-    console.log("syncComplete callback call data: " + data);
+    console.log("callback call data: " + data);
 });
 ```