Method names in Swift

Question

In Objective-C we have method names like application:didFinishLaunchingWithOptions:, but in Swift the method for the same job looks different.

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
    // Override point for customization after application launch.
    return true
}

Is the name of this method simply application since everything else are just parameters? Or is it called application didFinishLaunchingWithOptions with a space in the name? I was looking for an official answer in the Apple Documentation but I could not find one.

Answer 1

The method is indeed called application, however didFinishLaunchingWithOptions is an external parameter name and:

If you provide an external parameter name for a parameter, that external name must always be used when you call the function.

Since there can be two functions called application with different external parameter names, we always have to specify the external parameters when referring to a function. So, the whole name of the function/method would be

application(_:didFinishLaunchingWithOptions:)

You are right there hasn't be any convention made yet for referring to Swift functions. The safest way to refer to a function now is to use the Obj-C convention.

application:didFinishLaunchingWithOptions:

Which is still used in all Apple documentation links.

This convention is used throughout Apple documentation.

Answer 2

The method is indeed “just” application.
Swift uses this more often, if you have a tableview for example almost all functions start with tableview

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {}

The parameters “define” the functions instead of the method.