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

let str = "123456789"
let intArray = map(str) { String($0).toInt() ?? 0 }

• map() iterates Characters in str
• String($0) converts Character to String
• .toInt() converts String to Int. If failed(??), use 0.

If you prefer for loop, try:

let str = "123456789"
var intArray: [Int] = []

for chr in str {
    intArray.append(String(chr).toInt() ?? 0)
}

OR, if you want to iterate indices of the String:

let str = "123456789"
var intArray: [Int] = []

for i in indices(str) {
    intArray.append(String(str[i]).toInt() ?? 0)
}

Answer 2

@rintaro's answer is correct, but I just wanted to add that you can use reduce to weed out any characters that can't be converted to an Int, and even display a warning message if that happens:

let str = "123456789"
let intArray = reduce(str, [Int]()) { (var array: [Int], char: Character) -> [Int] in
    if let i = String(char).toInt() {
        array.append(i)
    } else {
        println("Warning: could not convert character \(char) to an integer")
    }
    return array
}

The advantages are:

• if intArray contains zeros you will know that there was a 0 in str, and not some other character that turned into a zero
• you will get told if there is a non-Int character that is possibly screwing things up.