Accepting parameters in a closure

When you create closures, they don’t have a name or space to write any parameters. That doesn’t mean they can’t accept parameters, just that they do so in a different way: they are listed inside the open braces.

To make a closure accept parameters, list them inside parentheses just after the opening brace, then write in so that Swift knows the main body of the closure is starting.

For example, we could make a closure that accepts a place name string as its only parameter like this:

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

One of the differences between functions and closures is that you don’t use parameter labels when running closures. So, to call driving() now we’d write this:

driving("London")