Swift How to Cast from Int? to String

Convert Int to String in Swift

Converting Int to String:

let x : Int = 42
var myString = String(x)

And the other way around - converting String to Int:

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

if (x != nil) {
    // Successfully converted String to Int
}

Or if you're using Swift 2 or 3:

let x: Int? = Int(myString)

swift How to cast from Int? to String

You can use string interpolation.

let x = 100
let str = "\(x)"

if x is an optional you can use optional binding

var str = ""
if let v = x {
   str = "\(v)"
}
println(str)

if you are sure that x will never be nil, you can do a forced unwrapping on an optional value.

var str = "\(x!)"

In a single statement you can try this

let str = x != nil ? "\(x!)" : ""

Based on @RealMae's comment, you can further shorten this code using the nil coalescing operator (??)

let str = x ?? ""

Converting Int to String in Swift

String cannot init with Int?, but it can with Int. Since String(int:Int) doesn't return an optional, you can get the effect you want with the same amount of code:

if let _duration = duration {
  viewDuration = String(_duration)
} else {
  viewDuration = ""
}

Cast Int? to a String in a Text Component

some examples, first unwrapping Int with default option

 Text("\(workDuration ?? 0)")

Second case not to show a default text, and not to draw object Text (paddings, modifiers associates)

 if let workDuration != nil { Text("\(workDuration ?? 0)") }

Third more elegant as suggested by George, same as second option

 if let workDuration = workDuration { Text("\(workDuration)") }

Four, following Rob Napier's comment, unwrapping your model

  struct Workout {
    var duration: Int?
    var durationDescription : String {
         "\(duration ?? 0)"
    }
  }
  
  struct ContentView: View {
    let workout = Workout(duration: 33) //sample

    var body: some View {
       Text("\(workout.durationDescription)")
    }
 }

 
  

Casting an Int as a String from a Realm result Swift

The issue isn't String(lastRecord?.time) being Optional. The issue is lastRecord being Optional, so you have to unwrap lastRecord, not the return value of String(lastRecord?.time).

if let lastRecord = lastRecord {
    previousRoundsLabel.text = "\(lastRecord.time)"
}

How to convert an Int to a Character in Swift

You can't convert an integer directly to a Character instance, but you can go from integer to UnicodeScalar to Character and back again:

let startingValue = Int(("A" as UnicodeScalar).value) // 65
for i in 0 ..< 26 {
    print(Character(UnicodeScalar(i + startingValue)))
}

Convert Int to String while decoding JSON in Swift

You can try

struct Person: Decodable {
    let name,age: String
    private enum CodingKeys : String, CodingKey {
          case name, age
    }
    init(from decoder: Decoder) throws {
       let container = try decoder.container(keyedBy: CodingKeys.self)
       name = try container.decode(String.self, forKey: .name)
        do {
            let years = try container.decode([String:Int].self, forKey: .age)
            age = "\(years["age_years"] ?? 0)"
        }
        catch {
            let years = try container.decode([String:String].self, forKey: .age)
            age = years["age_years"] ?? "0"
        }
     
    }
}

Swift simplify optional Int to String conversion with nil coalescing operator

Here's one solution:

let str = "\(num.map { String($0) } ?? "?") foo"

This returns "? foo" if num is nil or it returns "42 foo" if num is set to 42.

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