Converting to Char/String from Ascii Int in Swift

Question

I\'m trying to convert the integer representation of an ascii character back into a string.

string += (char) int;

In other languages like J

Answer 1

Here's a production-ready solution in Swift 3:

extension String {
    init(unicodeScalar: UnicodeScalar) {
        self.init(Character(unicodeScalar))
    }


    init?(unicodeCodepoint: Int) {
        if let unicodeScalar = UnicodeScalar(unicodeCodepoint) {
            self.init(unicodeScalar: unicodeScalar)
        } else {
            return nil
        }
    }


    static func +(lhs: String, rhs: Int) -> String {
        return lhs + String(unicodeCodepoint: rhs)!
    }


    static func +=(lhs: inout String, rhs: Int) {
        lhs = lhs + rhs
    }
}

Usage:

let a = String(unicodeCodepoint: 42) // "*"
var b = a + 126 // "*~"
b += 33 // "*~!"

Note that this works with all ASCII and Unicode codepoints, so you can do this:

var emoji = String(unicodeCodepoint: 0x1F469)! // "