NEW: Join my free 100 Days of SwiftUI challenge today! >>

Creating basic closures

Swift lets us use functions just like any other type such as strings and integers. This means you can create a function and assign it to a variable, call that function using that variable, and even pass that function into other functions as parameters.

Functions used in this way are called closures, and although they work like functions they are written a little differently.

Let’s start with a simple example that prints a message:

let driving = {
    print("I'm driving in my car")
}

That effectively creates a function without a name, and assigns that function to driving. You can now call driving() as if it were a regular function, like this:

driving()

SPONSORED Instabug helps you identify and resolve severe crashes quickly. You can retrace in-app events and know exactly which line of code caused the crash along with environment details, network logs, repro steps, and the session profiler. Ask more questions or keep users up-to-date with in-app replies straight from your dashboard. Instabug takes data privacy seriously, so no one sees your data but you! See more detailed features comparison and try Instabug's crash reporting SDK for free.

BUY OUR BOOKS
Buy Pro Swift Buy Swift Design Patterns Buy Testing Swift Buy Hacking with iOS Buy Swift Coding Challenges Buy Swift on Sundays Volume One Buy Server-Side Swift (Vapor Edition) Buy Advanced iOS Volume One Buy Advanced iOS Volume Two Buy Advanced iOS Volume Three Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with macOS Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Server-Side Swift (Kitura Edition) Buy Beyond Code

Was this page useful? Let us know!

Average rating: 4.6/5