In Swift, i cant cast Int to String by:

```
var iString:Int = 100
var strString = String(iString)

```

But my variable in Int? , there for error: `Cant invoke 'init' with type '@Ivalue Int?'` 

Example

```
let myString : String = "42"
let x : Int? = myString.toInt()

if (x != null) {
    // Successfully converted String to Int
    //And how do can i convert x to string???
}

```