Manning, Jon, Paris Buttfield-Addison, and Tim Nugent. Swift Development with Cocoa. O'Reilly Media, 2014

Functions can be nested.

Functions are a

first-class type

Functions can optionally have external parameter names

Functions:

Value Capture

func createIncrementor(incrementAmount: Int) -> () -> Int {

    var amount = 0

    func incrementor() -> Int {

        amount += incrementAmount

        return amount

    }

    return incrementor

}

var incrementByTen = createIncrementor(10)

incrementByTen() //10

incrementByTen() //20

var incrementByFifteen = createIncrementor(15)

incrementByFifteen() //15

incrementByFifteen() //30

Due to time constraints, we decided to remove a discussion of value capture from our presentation.

But it's still interesting, so read and enjoy!