Simple Swift optional example both long and short version.

swift_optional

let numberOfWheels = [“car”: 4, “bike”: 1, "legs" : 0]
let wheelCount: Int? = numberOfWheels[“unicycle”]

// Now to unwrap wheelCount, if wheelCount is nil then
// the if block is never executed

// Long way

if wheelCount == nil {
    println(“unicycle wasn’t found”)
} else {
    let actualWheelCount = wheelCount!
    println(“\(actualWheelCount) wheels”)
}

// Short way

if let actualWheelCount = wheelCount {
    println(“\(actualWheelCount) wheels")
}