Type 'ViewController' does not conform to protocol 'UITableViewDataSource'

You should implement all the required methods before the last }, but you have written them outside of the UIViewController. Also, you need to change the func for number of lines.

the suggested edit

class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate {
    @IBOutlet weak var table: UITableView!


    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func tableView(tableView:UITableView!, numberOfRowsInSection section:Int) -> Int
    {
        return 20
    }

    func tableView(tableView: UITableView!, cellForRowAtIndexPath indexPath: NSIndexPath!) -> UITableViewCell!
    {
        let cell:UITableViewCell=UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: "mycell")
        cell.textLabel.text="row#\(indexPath.row)"
        cell.detailTextLabel.text="subtitle#\(indexPath.row)"

        return cell
    }
}

Try removing the ! on your func. That did the job for me

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell
{
    let cell:UITableViewCell=UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: "mycell")
    cell.textLabel.text="row#\(indexPath.row)"
    cell.detailTextLabel.text="subtitle#\(indexPath.row)"

    return cell
}

You need to implement all the required methods of UITableViewDataSource in order to get rid of that error.

Basically... you're missing:

func tableView(tableView:UITableView!, numberOfRowsInSection section:Int) -> Int {
    //return XX
}

I had the same problem, things would workout rather easily in Objective-C, probably because we are more familiar with it at the moment, but in this case, swift is very new, therefore, the its error notifications are rather vague.

While I was implementing the UITableView based application, and I ran into this problem. I opened up the implementation file for UITableView by pressing command and clicking on UITableView. In implementation file, we can clearly see that two functions are mandatory to implement,

1. func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int
2. func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell

I arrived at this post and started to put things together while keeping my meager knowledge of objective-C programming in mind. Reason for the error being that a table view is defined by two elements, first the section and rows in a section, and second the tableview cells. By default there is at least one section in the table view, but we need conformance about number of rows in a section. Secondly, we need to know which cell are we going to present in a particular row in a section. Regardless,even if we are using default UITableViewCell, we still need an identifier to access it in order to set its subviews or properties. I hope it was helpful, A bit soft criticism will be appreciated since I am myself very new to Swift :)

The following code didn't work for me on iOS 8.1. in XCode 6.1.1. This code works:

import UIKit

class ViewController : UIViewController,UITableViewDelegate,UITableViewDataSource {

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int{
        //currently only a testing number
        return 25
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell{

        var cell:UITableViewCell=UITableViewCell(style: UITableViewCellStyle.Subtitle, reuseIdentifier: "mycell")
        cell.textLabel?.text = "row#\(indexPath.row)"
        cell.detailTextLabel?.text = "subtitle#\(indexPath.row)"
        return cell
    }


    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}