swift How to cast from Int? to String

Question

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:

Answer 1

You need to "unwrap" your optional in order to get to the real value inside of it as described here. You unwrap an option with "!". So, in your example, the code would be:

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

if (x != null) {
    // Successfully converted String to Int
    // Convert x (an optional) to string by unwrapping
    let myNewString = String(x!)
}

Or within that conditional, you could use string interpolation:

let myNewString = "\(x!)" // does the same thing as String(x!)