Ytukyg

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

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

Swift 3.1

Now in Xcode 7.1 and Swift 2.1

var singleChar = "a"



singleChar.unicodeScalars.first?.value

Here's my implementation, it returns an array of the ASCII values.

extension String {



    func asciiValueOfString() -> [UInt32] {



      var retVal = [UInt32]()

      for val in self.unicodeScalars where val.isASCII() {

          retVal.append(UInt32(val))

      }

      return retVal

    }

}

Note: Yes it's Swift 2 compatible.

The way you're doing it is right. If you don't like the verbosity of the indexing, you can avoid it by cycling through the unicode scalars:

var x : UInt32 = 0

let char = "a"

for sc in char.unicodeScalars {x = sc.value; break}

You can actually omit the break in this case, of course, since there is only one unicode scalar.

Or, convert to an Array and use Int indexing (the last resort of the desperate):

let char = "a"

let x = Array(char.unicodeScalars)[0].value

A slightly shorter way of doing this could be:

first(singleChar.unicodeScalars)!.value

As with the subscript version, this will crash if your string is actually empty, so if you’re not 100% sure, use the optional:

if let ascii = first(singleChar.unicodeScalars)?.value {



}

Or, if you want to be extra-paranoid,

if let char = first(singleChar.unicodeScalars) where char.isASCII() {

    let ascii = char.value

}

var singchar = "a" as NSString



print(singchar.character(at: 0))

Swift 3.1

Swift 4.1

https://oleb.net/blog/2017/11/swift-4-strings/

let flags = "99_problems"

flags.unicodeScalars.map {

    "(String($0.value, radix: 16, uppercase: true))"

}

Result:

["39", "39", "5F", "70", "72", "6F", "62", "6C", "65", "6D", "73"]

Swift 4.2

The easiest way to get ASCII values from a Swift string is below

let str = "Swift string"

for ascii in str.utf8 {

    print(ascii)

}

Output:

83

119

105

102

116

32

115

116

114

105

110

103

Swift 4

print("c".utf8["c".utf8.startIndex])

or

let cu = "c".utf8

print(cu[cu.startIndex])

Both print 99. Works for any ASCII character.

There's also the UInt8(ascii: Unicode.Scalar) initializer on UInt8.

var singleChar = "a"

UInt8(ascii: singleChar.unicodeScalars[singleChar.startIndex])

Swift 4+

Char to ASCII

let charVal = String(ch).unicodeScalars

var asciiVal = charVal[charVal.startIndex].value

ASCII to Char

let char = Character(UnicodeScalar(asciiVal)!)