update docs

Signed-off-by: NAnnie_wang <annie.wangli@huawei.com>

en/application-dev/database/database-distributedobject-guidelines.md

@@ -43,7 +43,7 @@ Call **on()** to subscribe to data changes of a distributed data object. When th
 | Class| API| Description| 
 | -------- | -------- | -------- |
 | DistributedDataObject| on(type: 'change', callback: Callback<{ sessionId: string, fields: Array&lt;string&gt; }>): void | Subscribes to data changes.| 
-| DistributedDataObject| off(type: 'change', callback?: Callback<{ sessionId: string, fields: Array&lt;string&gt; }>): void | Unsubscribes from data changes. **Callback**: specifies callback used to return changes of the distributed data object. If this parameter is not specified, all callbacks related to data changes will be unregistered.|
+| DistributedDataObject| off(type: 'change', callback?: Callback<{ sessionId: string, fields: Array&lt;string&gt; }>): void | Unsubscribes from data changes. <br>**Callback**: specifies callback used to return changes of the distributed data object. If this parameter is not specified, all callbacks related to data changes will be unregistered.|
 
 ### Observing Online or Offline Status
 
@@ -93,7 +93,7 @@ The following example shows how to implement a distributed data object synchroni
    // After learning that the device goes online, the remote object synchronizes data. That is, name changes to jack and age to 18.
    ```
    
-4. Observe the data changes of the distributed data object. You can subscribe to data changes of the peer object. When the data in the peer object changes, a callback will be called to return the data changes.
+4. Observe the data changes of the distributed data object. You can subscribe to data changes of the remote object. When the data in the remote object changes, a callback will be called to return the data changes.
 
    The sample code is as follows:
    

en/application-dev/reference/apis/js-apis-data-preferences.md

@@ -32,14 +32,14 @@ Reads a **Preferences** persistence file and loads data to the **Preferences** i
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | context | [Context](js-apis-Context.md) | Yes| Context of the application or functionality.|
   | name | string | Yes| Name of the **Preferences** instance persistence file.|
   | callback | AsyncCallback<[Preferences](#preferences)> | Yes| Callback used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -77,18 +77,18 @@ Reads a **Preferences** persistence file and loads data to the **Preferences** i
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | context | [Context](js-apis-Context.md) | Yes| Context of the application or functionality.|
-  | name | string | Yes| Name of the** Preferences** instance persistence file.|
+  | name | string | Yes| Name of the **Preferences** instance persistence file.|
 
-- Return value
+**Return value**
   | Type| Description|
   | -------- | -------- |
   | Promise<[Preferences](#preferences)> | Promise used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -126,14 +126,14 @@ Once a **Preferences** persistence file is deleted, the **Preferences** instance
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | context | [Context](js-apis-Context.md) | Yes| Context of the application or functionality.|
   | name | string | Yes| Name of the **Preferences** instance persistence file.|
   | callback | AsyncCallback<void> | Yes| Callback used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -159,18 +159,18 @@ Once a **Preferences** persistence file is deleted, the **Preferences** instance
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | context | [Context](js-apis-Context.md) | Yes| Context of the application or functionality.|
-  | name | string | Yes| Name of the** Preferences** instance persistence file.|
+  | name | string | Yes| Name of the **Preferences** instance persistence file.|
 
-- Return value
+**Return value**
   | Type| Description|
   | -------- | -------- |
   | Promise<void> | Promise used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -196,14 +196,14 @@ When a **Preferences** singleton instance is removed, this instance cannot be us
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | context | [Context](js-apis-Context.md) | Yes| Context of the application or functionality.|
-  | name | string | Yes| Name of the** Preferences** instance persistence file.|
+  | name | string | Yes| Name of the **Preferences** instance persistence file.|
   | callback | AsyncCallback<void> | Yes| Callback used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -230,18 +230,18 @@ When a **Preferences** singleton instance is removed, this instance cannot be us
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | context | [Context](js-apis-Context.md) | Yes| Context of the application or functionality.|
-  | name | string | Yes| Name of the** Preferences** instance persistence file.|
+  | name | string | Yes| Name of the **Preferences** instance persistence file.|
 
-- Return value
+**Return value**
   | Type| Description|
   | -------- | -------- |
   | Promise<void> | Promise used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -270,14 +270,14 @@ Obtains the value of a key. If the value is null or a non-default value, the def
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | key | string | Yes| Key of the data to obtain. It cannot be empty.|
   | defValue | [ValueType](#valuetype) | Yes| Default value to be returned. It can be a number, string, or Boolean value.|
   | callback | AsyncCallback<ValueType> | Yes| Callback used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -308,18 +308,18 @@ Obtains the value of a key. If the value is null or a non-default value, the def
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | key | string | Yes| Key of the data to obtain. It cannot be empty.|
   | defValue | [ValueType](#valuetype) | Yes| Default value to be returned. It can be a number, string, or Boolean value.|
 
-- Return value
+**Return value**
   | Type| Description|
   | -------- | -------- |
   | Promise<ValueType> | Promise used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -348,14 +348,14 @@ Puts a new value to this **Preferences** instance and its persistence file. This
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | key | string | Yes| Key of the data. It cannot be empty.|
   | value | [ValueType](#valuetype) | Yes| New value to store. It can be a number, string, or Boolean value.|
   | callback | AsyncCallback<void> | Yes| Callback used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -386,18 +386,18 @@ Puts a new value to this **Preferences** instance and its persistence file. This
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | key | string | Yes| Key of the data. It cannot be empty.|
   | value | [ValueType](#valuetype) | Yes| New value to store. It can be a number, string, or Boolean value.|
 
-- Return value
+**Return value**
   | Type| Description|
   | -------- | -------- |
   | Promise<void> | Promise used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -426,18 +426,18 @@ Checks whether this **Preferences** instance contains data with a given key. Thi
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | key | string | Yes| Key of the data to check. It cannot be empty.|
   | callback | AsyncCallback<boolean> | Yes| Callback used to return the result.|
 
-- Return value
+**Return value**
   | Type| Description|
   | -------- | -------- |
   | boolean | Returns **true** if the **Preferences** instance contains data with the specified key; returns **false** otherwise.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -472,17 +472,17 @@ Checks whether this **Preferences** instance contains data with a given key. Thi
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | key | string | Yes| Key of the data to check. It cannot be empty.|
 
-- Return value
+**Return value**
   | Type| Description|
   | -------- | -------- |
   | Promise<boolean> | Promise used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -515,13 +515,13 @@ Deletes a KV pair of the specified key from this **Preferences** instance. This
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | key | string | Yes| Key of the KV pair to delete. It cannot be empty.|
   | callback | AsyncCallback<void> | Yes| Callback used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -552,17 +552,17 @@ Deletes a KV pair of the specified key from this **Preferences** instance. This
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | key | string | Yes| Key of the KV pair to delete. It cannot be empty.|
 
-- Return value
+**Return value**
   | Type| Description|
   | -------- | -------- |
   | Promise<void> | Promise used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -591,12 +591,12 @@ Saves the modification to this **Preferences** instance and synchronizes the mod
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | callback | AsyncCallback<void> | Yes| Callback used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -627,12 +627,12 @@ Saves the modification to this **Preferences** instance and synchronizes the mod
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Return value
+**Return value**
   | Type| Description|
   | -------- | -------- |
   | Promise<void> | Promise used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -661,12 +661,12 @@ Clears data of this **Preferences** instance. This API uses an asynchronous call
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Mandatory| Description|
   | -------- | -------- | -------- | -------- |
   | callback | AsyncCallback<void> | Yes| Callback used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -697,12 +697,12 @@ Clears data of this **Preferences** instance. This API uses a promise to return
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Return value
+**Return value**
   | Type| Description|
   | -------- | -------- |
   | Promise<void> | Promise used to return the result.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -731,13 +731,13 @@ Subscribes to data changes. When the value of the subscribed key changes, a call
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Description|
   | -------- | -------- | -------- |
   | type | string | Event type. The value **change** indicates data change events.|
   | callback | Callback<{ key : string }> | Callback used to return data changes.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'
@@ -779,13 +779,13 @@ Unsubscribes from data changes.
 
 **System capability**: SystemCapability.DistributedDataManager.Preferences.Core
 
-- Parameters
+**Parameters**
   | Name| Type| Description|
   | -------- | -------- | -------- |
   | type | string | Event type. The value **change** indicates data change events.|
   | callback | Callback<{ key : string }> | Callback used to return data changes.|
 
-- Example
+**Example**
   ```ts
   import Ability from '@ohos.application.Ability'
   import data_preferences from '@ohos.data.preferences'