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 ViRE offers discoverable way of working with regex. It provides really readable regex experience, code complete & cheat sheet, unit tests, powerful replace system, step-by-step search & replace, regex visual scheme, regex history & playground. ViRE is available on Mac & iPad.

Download on the App Store

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