How can I write an empty case in Swift?

To prevent the error:

Case label in a switch should have at least one executable statement

... use () in case label like in the following example. Also works with default label.

let a = 1
switch a {
case 1:
    ()
case 2:
    println("2")
default:
    ()
}

let a = 50
switch a {
case 0..10:
    break // Break the switch immediately
case 10..100:
    println("between 10 and 100")
default:
    println("100 and above")
}

Keyword break is optional, but not in this case :)