How can I convert my device token (NSData) into an NSString?

Question

I am implementing push notifications. I\'d like to save my APNS Token as a String.

- (void)application:(UIApplication *)application
didRegisterForRemoteNotif         


        

Answer 1

Functional Swift version

One liner:

let hexString = UnsafeBufferPointer(start: UnsafePointer(data.bytes),
count: data.length).map { String(format: "%02x", $0) }.joinWithSeparator("")

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Here's in a reusable and self documenting extension form:

extension NSData {
    func base16EncodedString(uppercase uppercase: Bool = false) -> String {
        let buffer = UnsafeBufferPointer(start: UnsafePointer(self.bytes),
                                                count: self.length)
        let hexFormat = uppercase ? "X" : "x"
        let formatString = "%02\(hexFormat)"
        let bytesAsHexStrings = buffer.map {
            String(format: formatString, $0)
        }
        return bytesAsHexStrings.joinWithSeparator("")
    }
}

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Alternatively, use reduce("", combine: +) instead of joinWithSeparator("") to be seen as a functional master by your peers.

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Edit: I changed String($0, radix: 16) to String(format: "%02x", $0), because one digit numbers needed to having a padding zero

(I don't know yet how to mark a question as a duplicate of this other one, so I just posted my answer again)