Swift - Using Selector in Swift

In Objective-C, you often encounter methods that accepts a Selector as the argument. A good example is the NSTimer's NSTimer.scheduledTimerWithTimeInterval() method:

- (void)onTimer {

}

    [NSTimer scheduledTimerWithTimeInterval:0.05

                                     target:self

                                   selector:@selector(onTimer)

                                   userInfo:nil

                                    repeats:YES];   

A selector is basically a name of a method that will be executed by another method. In Objective-C, to pass in a selector argument you use the @selector() keyword together with the name of the method. 

In Swift, you can simply pass in the name of the method as a string, like this:

func onTimer() {

}

        NSTimer.scheduledTimerWithTimeInterval(0.05,

            target:self,

            selector:"onTimer",

            userInfo:nil,

        repeats:true)