# subscribe_topic
# Function
| Function Name | Description | Level |
|---|---|---|
| subscribe_topic | add a topic into the user forum subscription list. | 3 |
Input Parameters:
| Name | Type | Required? | Description | Level |
|---|---|---|---|---|
| topic_id | String | yes | topic id of the forum to be subscribed. | 3 |
Output Parameters:
| Name | Type | Required? | Description | Level |
|---|---|---|---|---|
| result | Boolean | yes | return true if the action is performed successfully. | 3 |
| result_text | byte[] | 3 |