How to Fetch JSON to Swift to tableView as Sections and Rows?

I want to ask how to implement the files as sections depends on userId then show all again in the tableview.

I'm started build simple project I fetched JSON file as decoder and show all in table view:

func fetchUsers(using url: String){
    let url = URL(string: url)!
    let _ = URLSession.shared.dataTask(with: url){ (data,response,error)
        in
        guard let data = data else {return}
        do{
            let objects = try JSONDecoder().decode([User].self, from: data)  // decode * ( Codable )
            self.users = objects
        } catch{
            print("error loading data cause: \(error)")
            }
        }.resume()
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    if let cell = tableView.dequeueReusableCell(withIdentifier: "users",for: indexPath) as? customeCellTableViewCell{
        let indexRow = users[indexPath.row]
        cell.dataModel(forModel: indexRow)
     return cell
    }
    return UITableViewCell()
}

private func numberOfUsers(in users: [User]) -> Int {
         
            return 1
        }
    
        func numberOfSections(in tableView: UITableView) -> Int {

            return numberOfUsers(in: self.users)
            
        }

Like @vadian mentions tuples should be avoided for this so here is an improved solution.

Instead of a tuple we can use a struct to hold the grouped data

struct UsersByID {
    let id: Int
    var users : [User]
}

then change the load function to

func load(withUsers users: [User]) {
    let dict = Dictionary(grouping: users) { return $0.userID }
    usersByID = dict.map { (key, values) in
        return UsersByID(id: key, users: values)
    }.sorted(by: { $0.id < $1.id })
}

The rest of the code is the same but replace key with id and value with users

---

Old solution

First create a dictionary to hold your sections (keys) and rows (values) as a property in the view controller

var usersByID = [(key: Int, value: [User])]()

then fill that dictionary using grouping:by: using the array from json

func load(withUsers users: [User]) {
    usersByID = Dictionary(grouping: users, by: { user in
        user.userID }).sorted(by: { $0.0 < $1.0})
}

then the table view functions use this dictionary

---

override func numberOfSections(in tableView: UITableView) -> Int {
    return usersByID.count
}

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return usersByID[section].value.count
}

override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
    return String(usersByID[section].key)
}

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "LabelCell", for: indexPath)

    let user = usersByID[indexPath.section].value[indexPath.row]
    cell.textLabel?.text = user.title
    //...

    return cell
}