Returning values from a closure

Closures can also return values, and they are written similarly to parameters: you write them inside your closure, directly before the in keyword.

To demonstrate this, we’re going to take our driving() closure and make it return its value rather than print it directly. Here’s the original:

let driving = { (place: String) in
    print("I'm going to \(place) in my car")
}

We want a closure that returns a string rather than printing the message directly, so we need to use -> String before in, then use return just like a normal function:

let drivingWithReturn = { (place: String) -> String in
    return "I'm going to \(place) in my car"
}

We can now run that closure and print its return value:

let message = drivingWithReturn("London")
print(message)

SPONSORED Are you tired of wasting time debugging your Swift app? Instabug’s SDK is here to help you minimize debugging time by providing you with complete device details, network logs, and reproduction steps with every bug report. All data is attached automatically, and it only takes a line of code to setup. Start your free trial now and get 3 months off exclusively for the Hacking with Swift Community.

Start your free trial!

Sponsor Hacking with Swift and reach the world's largest Swift community!