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 Join a FREE crash course for mid/senior iOS devs who want to achieve an expert level of technical and practical skills – it’s the fast track to being a complete senior developer! Hurry up because it'll be available only until April 28th.

Click to save your free spot now

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