When you want to get a `String` from an `Int` and format this `String`, you need to use `NSNumberFormatter`.
The following code creates a `NSNumberFormatter` that has at least two integer digits:
let formatter = NSNumberFormatter()
formatter.minimumIntegerDigits = 2
for myInt in 1...3 {
let str = formatter.stringFromNumber(myInt)
println(str)
}