Two network requests with DispatchGroup.swift

// Create a dispatch group
let userListDispatchGroup = DispatchGroup()

// Get List of Users
userListDispatchGroup.enter()
Alamofire.request("https://httpbin.org/get?users").validate().responseJSON { response in

    switch response.result {
    case .success:
        print("Get User Successful")
        // put user into users array
		...
		
    case .failure(let error):
        print(error)
    }
    
    // leave the dispatch group after the network request is complete and data is parsed
    userListDispatchGroup.leave()
}

// Get List of Avatars
userListDispatchGroup.enter()
Alamofire.request("https://httpbin.org/get?avatars").validate().responseJSON { response in
	
    switch response.result {
    case .success:
        print("Get Avatars Successful")
        // put avatar into avatars array
		....
		
    case .failure(let error):
        print(error)
    }
    
    // leave the dispatch group after the network request is complete and data is parsed
    userListDispatchGroup.leave()
}

// after both network request complete, code inside this closure will be called
// queue: .main means the main queue, always use main queue to update UI
userListDispatchGroup.notify(queue: .main) {
	print("Both get users and get avatars has completed 👌")
	self.tableView.reloadData()
}