Convert optional string to int in Swift

Question

I am having troubles while converting optional string to int.

   println("str_VAR = \(str_VAR)")      
   println(str_VAR.toInt())

Result is

   str_VAR = Optional(100)
   nil

And i want it to be

   str_VAR = Optional(100)
   100

Answer 1

At the time of writing, the other answers on this page used old Swift syntax. This is an update.

Convert Optional String to Int: String? -> Int

let optionalString: String? = "100"
if let string = optionalString, let myInt = Int(string) {
     print("Int : \(myInt)")
}

This converts the string "100" into the integer 100 and prints the output. If optionalString were nil, hello, or 3.5, nothing would be printed.

Also consider using a guard statement.

Answer 2

Try this:

if let i = str_VAR?.toInt() {
    println("\(i)")
}