What's the simplest way to convert from a single character String to an ASCII value in Swift?

I just want to get the ASCII value of a single char string in Swift. This is how I'm currently doing it:

var singleChar = "a"
println(singleChar.unicodeScalars[singleChar.unicodeScalars.startIndex].value) //prints: 97

This is so ugly though. There must be a simpler way.

edit/update Swift 5.2 or later

extension StringProtocol {
    var asciiValues: [UInt8] { compactMap(\.asciiValue) }
}

"abc".asciiValues  // [97, 98, 99]

In Swift 5 you can use the new character properties isASCII and asciiValue

Character("a").isASCII       // true
Character("a").asciiValue    // 97

Character("á").isASCII       // false
Character("á").asciiValue    // nil

Old answer

You can create an extension:

Swift 4.2 or later

extension Character {
    var isAscii: Bool {
        return unicodeScalars.allSatisfy { $0.isASCII }
    }
    var ascii: UInt32? {
        return isAscii ? unicodeScalars.first?.value : nil
    }
}

extension StringProtocol {
    var asciiValues: [UInt32] {
        return compactMap { $0.ascii }
    }
}

Character("a").isAscii  // true
Character("a").ascii    // 97

Character("á").isAscii  // false
Character("á").ascii    // nil

"abc".asciiValues            // [97, 98, 99]
"abc".asciiValues[0]         // 97
"abc".asciiValues[1]         // 98
"abc".asciiValues[2]         // 99

UnicodeScalar("1")!.value // returns 49

Swift 3.1

Now in Xcode 7.1 and Swift 2.1

var singleChar = "a"

singleChar.unicodeScalars.first?.value

You can use NSString's characterAtIndex to accomplish this...

var singleCharString = "a" as NSString
var singleCharValue = singleCharString.characterAtIndex(0)
println("The value of \(singleCharString) is \(singleCharValue)")  // The value of a is 97