Convert Int to String in Swift

I'm trying to work out how to cast an Int into a String in Swift.

I figure out a workaround, using NSNumber but I'd love to figure out how to do it all in Swift.

let x : Int = 45
let xNSNumber = x as NSNumber
let xString : String = xNSNumber.stringValue

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)

Check the Below Answer:

let x : Int = 45
var stringValue = "\(x)"
print(stringValue)

Here are 4 methods:

var x = 34
var s = String(x)
var ss = "\(x)"
var sss = toString(x)
var ssss = x.description

I can imagine that some people will have an issue with ss. But if you were looking to build a string containing other content then why not.

In Swift 3.0:

var value: Int = 10
var string = String(describing: value)

Swift 4:

let x:Int = 45
let str:String = String(describing: x)

Developer.Apple.com > String > init(describing:)

> The String(describing:) initializer is the preferred way to convert an instance of any type to a string.

Custom String Convertible

Just for completeness, you can also use:

let x = 10.description

or any other value that supports a description.

Swift 4:

Trying to show the value in label without Optional() word.

here x is a Int value using.

let str:String = String(x ?? 0)

To save yourself time and hassle in the future you can make an Int extension. Typically I create a shared code file where I put extensions, enums, and other fun stuff. Here is what the extension code looks like:

extension Int
{
    func toString() -> String
    {
        var myString = String(self)
        return myString
    }
}

Then later when you want to convert an int to a string you can just do something like:

var myNumber = 0
var myNumberAsString = myNumber.toString()

in swift 3.0 this is how we can convert Int to String and String to Int

//convert Integer to String in Swift 3.0

let theIntegerValue :Int = 123  // this can be var also
let theStringValue :String = String(theIntegerValue)


//convert String to Integere in Swift 3.0


let stringValue : String = "123"
let integerValue : Int = Int(stringValue)!

for whatever reason the accepted answer did not work for me. I went with this approach:

var myInt:Int = 10
var myString:String = toString(myInt)

Multiple ways to do this :

var str1:String="\(23)"
var str2:String=String(format:"%d",234)

Swift 2:

var num1 = 4
var numString = "56"
var sum2 = String(num1) + numString
var sum3 = Int(numString)

let intAsString = 45.description     // "45"
let stringAsInt = Int("45")          // 45

Swift String performance

A little bit about performance UI Testing Bundle on iPhone 7(real device) with iOS 14

let i = 0
lt result1 = String(i) //0.56s 5890kB
lt result2 = "\(i)" //0.624s 5900kB
lt result3 = i.description //0.758s 5890kB

import XCTest

class ConvertIntToStringTests: XCTestCase {
    let count = 1_000_000
    
    func measureFunction(_ block: () -> Void) {
        let metrics: [XCTMetric] = [
            XCTClockMetric(),
            XCTMemoryMetric()
        ]
        let measureOptions = XCTMeasureOptions.default
        measureOptions.iterationCount = 5
        
        measure(metrics: metrics, options: measureOptions) {
            block()
        }
    }

    func testIntToStringConstructor() {
        var result = ""
        measureFunction {
            for i in 0...count {
                result += String(i)
            }
        }
    }
    
    func testIntToStringInterpolation() {
        var result = ""
        measureFunction {
            for i in 0...count {
                result += "\(i)"
            }
        }
    }
    
    func testIntToStringDescription() {
        var result = ""
        measureFunction {
            for i in 0...count {
                result += i.description
            }
        }
    }
}

iam using this simple approach

String to Int:

 var a = Int()
var string1 = String("1")
a = string1.toInt()

and from Int to String:

var a = Int()
a = 1
var string1 = String()
 string1= "\(a)"

Convert Unicode Int to String

For those who want to convert an Int to a Unicode string, you can do the following:

let myInteger: Int = 97

// convert Int to a valid UnicodeScalar
guard let myUnicodeScalar = UnicodeScalar(myInteger) else {
    return ""
}

// convert UnicodeScalar to String
let myString = String(myUnicodeScalar)

// results
print(myString) // a

Or alternatively:

let myInteger: Int = 97
if let myUnicodeScalar = UnicodeScalar(myInteger) {
    let myString = String(myUnicodeScalar)
}

I prefer using String Interpolation

let x = 45
let string = "\(x)"

Each object has some string representation. This makes things simpler. For example if you need to create some String with multiple values. You can also do any math in it or use some conditions

let text = "\(count) \(count > 1 ? "items" : "item") in the cart. Sum: $\(sum + shippingPrice)"

exampleLabel.text = String(yourInt)

To convert String into Int

var numberA = Int("10")

Print(numberA) // It will print 10

To covert Int into String

var numberA = 10

1st way)

print("numberA is \(numberA)") // It will print 10

2nd way)

var strSomeNumber = String(numberA)

or

var strSomeNumber = "\(numberA)"

In swift 3.0, you may change integer to string as given below

let a:String = String(stringInterpolationSegment: 15)

Another way is

let number: Int = 15
let _numberInStringFormate: String = String(number)

//or any integer number in place of 15

let a =123456888
var str = String(a)

OR

var str = a as! String

If you like swift extension, you can add following code

extension Int
{
    var string:String {
        get {
            return String(self)
        }
    }
}

then, you can get string by the method you just added

var x = 1234
var s = x.string

let Str = "12"
let num: Int = 0
num = Int (str)