How to convert a String (numeric) in a Int array in Swift

Question

I\'d like to know how can I convert a String in an Int array in Swift. In Java I\'ve always done it like this:

String myString = \"123456789\";
int[] myArray = n         


        

Answer 1

Swift 3: Functional Approach

1. Split the String into separate String instances using: components(separatedBy separator: String) -> [String]

Reference: Returns an array containing substrings from the String that have been divided by a given separator.

2. Use the flatMap Array method to bypass the nil coalescing while converting to Int

Reference: Returns an array containing the non-nil results of calling the given transformation with each element of this sequence.

Implementation

let string = "123456789"
let intArray = string.components(separatedBy: "").flatMap { Int($0) }

Answer 2

Swift 3

Int array to String

let arjun = [1,32,45,5]
    print(self.get_numbers(array: arjun))

 func get_numbers(array:[Int]) -> String {
        let stringArray = array.flatMap { String(describing: $0) }
        return stringArray.joined(separator: ",")

String to Int Array

let arjun = "1,32,45,5"
    print(self.get_numbers(stringtext: arjun))

    func get_numbers(stringtext:String) -> [Int] {
    let StringRecordedArr = stringtext.components(separatedBy: ",")
    return StringRecordedArr.map { Int($0)!}   
}

Answer 3

You can use flatMap to convert the characters into a string and coerce the character strings into an integer:

Swift 2 or 3

let string = "123456789"
let digits = string.characters.flatMap{Int(String($0))}
print(digits)   // [1, 2, 3, 4, 5, 6, 7, 8, 9]"

Swift 4

let string = "123456789"
let digits = string.flatMap{Int(String($0))}
print(digits)   // [1, 2, 3, 4, 5, 6, 7, 8, 9]"

Swift 4.1

let digits = string.compactMap{Int(String($0))}

Swift 5 or later

We can use the new Character Property wholeNumberValue https://developer.apple.com/documentation/swift/character/3127025-wholenumbervalue

let digits = string.compactMap{$0.wholeNumberValue}

Answer 4

let array = "0123456789".compactMap{ Int(String($0)) }
print(array)

Answer 5

Swift 3 update:

@appzYourLife : That's correct toInt() method is no longer available for String in Swift 3. As an alternative what you can do is :

intArray.append(Int(String(chr)) ?? 0)

Enclosing it within Int() converts it to Int.

Answer 6

var myString = "123456789"
var myArray:[Int] = []

for index in 0..<countElements(myString) {
    var myChar = myString[advance(myString.startIndex, index)]
    myArray.append(String(myChar).toInt()!)
}

println(myArray)   // [1, 2, 3, 4, 5, 6, 7, 8, 9]"

To get the iterator pointing to a char from the string you can use advance

The method to convert string to int in Swift is toInt()