> ## Documentation Index
> Fetch the complete documentation index at: https://cometchat-013b37f0.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Join A Group

## Join a Group

In order to start participating in group conversations, you will have to join a group. You can do so using the `joinGroup()` method.

<Tabs>
  <Tab title="Swift">
    ```swift theme={null}
    let guid = "cometchat-guid-11";
    let password = nil; // mandatory in case of password protected group type

    CometChat.joinGroup(GUID: guid, groupType: .public, password: nil, onSuccess: { (group) in

      print("Group joined successfully. " + group.stringValue())

    }) { (error) in

      print("Group joining failed with error:" + error!.errorDescription);
    }
    ```
  </Tab>

  <Tab title="Objective C">
    ```objc theme={null}
    NSString *guid = @"cometchat-guid-101";
    NSString *password = nil ; // mandatory in case of password protected group type

    [CometChat joinGroupWithGUID:guid groupType:groupTypePublic password:password onSuccess:^(Group * group) {

        // Success
        NSLog(@"Group joined successfully: %@",[group stringValue]);

    } onError:^(CometChatException * error) {

        // Error
        NSLog(@"Group joining failed with exception: %@",[error errorDescription])
    }];
    ```
  </Tab>
</Tabs>

The `joinGroup()` method takes four parameters

| Parameter | Description                                                                             |
| --------- | --------------------------------------------------------------------------------------- |
| GUID      | The `GUID` of the group you would like to join                                          |
| groupType | Type of the group. CometChat provides 3 types of groups viz. .public .private .password |
| password  | The password is mandatory in case of a `.password` protected the group.                 |

Once you have joined a group successfully, you can send and receive messages in that group.

CometChat keeps a track of the groups joined and you do not need to join the group every time you want to communicate in the group.

You can identify if a group is joined using the `hasJoined` parameter in the `Group` object.

## Real-time Group Member Joined Events

*In other words, as a recipient, how do I know when someone joins a group?*

To receive Real-Time Events for the same, you need to implement the `onMemberAddedToGroup()` method of the `GroupListener` class.

<Tabs>
  <Tab title="Swift">
    ```swift theme={null}
    extension AppDelegate: CometChatGroupDelegate {

      func onMemberAddedToGroup(action: ActionMessage, addedBy: User, addedUser: User, addedTo: Group) {
          //When any member is added in the group this function will be called
      }

    }
    ```
  </Tab>

  <Tab title="Objective C">
    ```objc theme={null}
    @interface ViewController ()<CometChatGroupDelegate>

    @end

    @implementation ViewController

    - (void)viewDidLoad {
        [super viewDidLoad];

        [CometChat setGroupdelegate:self];
    }

    - (void)onMemberAddedToGroup:(Action *)action addedBy:(User * _Nonnull)addedBy addedUser:(User * _Nonnull)addedUser addedTo:(Group * _Nonnull)addedTo {
        //When any member is added in the group this function will be called
    }

    @end
    ```
  </Tab>
</Tabs>

## Missed Group Member Joined Events

*In other words, as a member of a group, how do I know if someone joins the group when my app is not running?*

When you retrieve the list of previous messages if a member has joined any group that the logged-in user is a member of, the list of messages will contain an `Action` message. An `Action` message is a sub-class of `BaseMessage` class.

For the group member joined the event, in the `Action` object received, the following fields can help you get the relevant information-

1. `action` - `joined`
2. `actionBy` - User object containing the details of the user who joined the group
3. `actionFor `- Group object containing the details of the group the user has joined