Simple conditions of switch/case statements in Swift

var str: String;
let monitorInchSize = 24
switch monitorInchSize {
    case 15:
        str = "too small"
    case 16,17,18:
        str = "good for the past decade"
    case 19...23:
        str = "for office work"
    case 24...27:
        str = "great choice"
    default:
        str = ""
}
//str is "great choice"