http://stackoverflow.com/questions/25339936/swift-double-to-string

var a:Double = 1.5
var b:String = String(format:”%f”, a)
print(“b: \(b)”) // b: 1.500000
With a different format:

var c:String = String(format:”%.1f”, a)
print(“c: \(c)”) // c: 1.5