> ## Documentation Index
> Fetch the complete documentation index at: https://www.cometchat.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# Join A Group
> Learn how to join public, password-protected, and private groups, and receive real-time join events using the CometChat iOS SDK.
```swift theme={null}
// Join a public group
CometChat.joinGroup(GUID: "GUID", groupType: .public, password: nil,
onSuccess: { group in }, onError: { error in })
// Join a password-protected group
CometChat.joinGroup(GUID: "GUID", groupType: .password, password: "password123",
onSuccess: { group in }, onError: { error in })
// Listen for member joined events via CometChatGroupDelegate
func onGroupMemberJoined(action: ActionMessage, joinedUser: User, joinedGroup: Group) { }
```
Join a group to start sending and receiving messages in it. Public groups can be joined freely, password groups require the correct password, and private groups require an admin to add you (no direct join).
## Join a Group
Use `joinGroup()` to join a group.
```swift theme={null}
let guid = "cometchat-guid-11"
let password: String? = 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())
}, onError: { (error) in
print("Group joining failed with error:" + error!.errorDescription)
})
```
```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) {
NSLog(@"Group joined successfully: %@", [group stringValue]);
} onError:^(CometChatException * error) {
NSLog(@"Group joining failed with exception: %@", [error errorDescription]);
}];
```
| Parameter | Description |
| ----------- | -------------------------------------- |
| `GUID` | The GUID of the group to join |
| `groupType` | `.public`, `.password`, or `.private` |
| `password` | Required for password-protected groups |
Once joined, you can send and receive messages in the group. CometChat tracks joined groups — you don't need to rejoin each session. Check `hasJoined` on the `Group` object to verify membership.
The method returns a [`Group`](/sdk/reference/entities#group) object with `hasJoined` set to `true`.
## Real-time Group Member Joined Events
Register a `CometChatGroupDelegate` to receive events when members join.
```swift theme={null}
class ViewController: UIViewController, CometChatGroupDelegate {
override func viewDidLoad() {
super.viewDidLoad()
CometChat.groupdelegate = self
}
func onGroupMemberJoined(action: ActionMessage, joinedUser: User, joinedGroup: Group) {
print("\(joinedUser.name ?? "") joined \(joinedGroup.name ?? "")")
}
func onMemberAddedToGroup(action: ActionMessage, addedBy: User, addedUser: User, addedTo: Group) {
print("\(addedUser.name ?? "") was added to \(addedTo.name ?? "")")
}
}
```
```objc theme={null}
@interface ViewController ()
@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
```
Always remove group listeners when they're no longer needed (e.g., on view dismissal). Failing to remove listeners can cause memory leaks and duplicate event handling.
## Missed Group Member Joined Events
When fetching message history, join events appear as [`Action`](/sdk/reference/messages#action) messages with:
* `action` — `"joined"`
* `actionBy` — [`User`](/sdk/reference/entities#user) who joined
* `actionFor` — [`Group`](/sdk/reference/entities#group) that was joined
***
## Next Steps
Allow members to leave a group
Fetch the list of members in a group
Send messages to group conversations
Programmatically add members to a group