How to Set UITableViewCellStyleSubtitle and dequeueReusableCell in Swift?

If you'd rather avoid optionality, you can make a subclass of UITableViewCell that looks something like this:

class SubtitleTableViewCell: UITableViewCell {

    override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
        super.init(style: .subtitle, reuseIdentifier: reuseIdentifier)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
}

Then register it using:

override func viewDidLoad() {
    super.viewDidLoad()
    self.tableView.register(SubtitleTableViewCell.self, forCellReuseIdentifier: reuseIdentifier)
}

This allows your cell customization code to be really nice:

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cell = tableView.dequeueReusableCell(withIdentifier: reuseIdentifier, for: indexPath)

    cell.textLabel?.text = "foo"
    cell.detailTextLabel?.text = "bar"

    return cell
}

Basically the same as other answers, but I get around dealing with nasty optionals (you can't return nil from -tableView:cellForRow:atIndexPath: in Swift) by using a computed variable:

Swift 3

override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cell: UITableViewCell = {
        guard let cell = tableView.dequeueReusableCell(withIdentifier: "UITableViewCell") else {
            // Never fails:
            return UITableViewCell(style: UITableViewCellStyle.value1, reuseIdentifier: "UITableViewCell")
        }
        return cell
    }()

    // (cell is non-optional; no need to use ?. or !)

    // Configure your cell:
    cell.textLabel?.text       = "Key"
    cell.detailTextLabel?.text = "Value"

    return cell
}

---

Edit:

Actually, it would be better to dequeue the cell using: tableView.dequeueReusableCell(withIdentifier:for:) instead.

This later variant of the function automatically instantiates a new cell if no one is available for reusing (exactly what my code does explicitly above), and therefore never returns nil.

Just building upon memmons' answer by cleaning it up Swift 2 style...

let cell = tableView.dequeueReusableCellWithIdentifier(reuseIdentifier) ?? UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: reuseIdentifier)

cell.detailTextLabel?.text = "some text"

return cell

Swift 3:

let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier) ?? UITableViewCell(style: .subtitle, reuseIdentifier: cellIdentifier)

cell.detailTextLabel?.text = ""

return cell

Keep in mind that UITableView is defined as an optional in the function, which means your initial cell declaration needs to check for the optional in the property. Also, the returned queued cell is also optional, so ensure you make an optional cast to UITableViewCell. Afterwards, we can force unwrap because we know we have a cell.

var cell:UITableViewCell? = 
tableView?.dequeueReusableCellWithIdentifier(reuseIdentifier) as? UITableViewCell
if (cell == nil)
{
   cell = UITableViewCell(style: UITableViewCellStyle.Subtitle, 
                reuseIdentifier: reuseIdentifier)
}
// At this point, we definitely have a cell -- either dequeued or newly created,
// so let's force unwrap the optional into a UITableViewCell
cell!.detailTextLabel.text = "some text"

return cell