Changing Value of Character Using Ascii Value in Swift

How to get string from ASCII code in Swift?

As a character:

let c = Character(UnicodeScalar(65))

Or as a string:

let s = String(UnicodeScalar(UInt8(65)))

Or another way as a string:

let s = "\u{41}"

(Note that the \u escape sequence is in hexadecimal, not decimal)

Converting to Char/String from Ascii Int in Swift

It may not be as clean as Java, but you can do it like this:

var string = ""
string.append(Character(UnicodeScalar(50)))

You can also modify the syntax to look more similar if you like:

//extend Character so it can created from an int literal
extension Character: IntegerLiteralConvertible {
    public static func convertFromIntegerLiteral(value: IntegerLiteralType) -> Character {
        return Character(UnicodeScalar(value))
    }
}

//append a character to string with += operator
func += (inout left: String, right: Character) {
    left.append(right)
}

var string = ""
string += (50 as Character)

Or using dasblinkenlight's method:

func += (inout left: String, right: Int) {
    left += "\(UnicodeScalar(right))"
}
var string = ""
string += 50

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

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

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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

Getting character ASCII value as an Integer in Swift

In Swift, a Character may not necessarily be an ASCII one. It would for example have no sense to return the ascii value of "quot; which requires a large unicode encoding. This is why asciiValue property has an optional UInt8 value, which is annotated UInt8?.

The simplest solution

Since you checked yourself that the character isAscii, you can safely go for an unconditional unwrapping with !:

var tempo:Int = Int(n.asciiValue!)     // <--- just change this line

A more elegant alternative

You could also take advantage of optional binding that uses the fact that the optional is nil when there is no ascii value (i.e. n was not an ASCII character):

if let tempo = n.asciiValue   // is true only if there is an ascii value
{
    temp += (Int(tempo) | key) 
}

How to convert sequence of ASCII code into string in swift 4?

As already mentioned decimal ASCII values are in range of 0-255 and can be more than 2 digits

Based on Sulthan's answer and assuming there are no characters < 32 (0x20) and > 199 (0xc7) in the text this approach checks the first character of the cropped string. If it's "1" the character is represented by 3 digits otherwise 2.

func convertAscii(asciiStr: String) {
    var source = asciiStr

    var result = ""

    while source.count >= 2 {
        let digitsPerCharacter = source.hasPrefix("1") ? 3 : 2
        let charBytes = source.prefix(digitsPerCharacter)
        source = String(source.dropFirst(digitsPerCharacter))
        let number = Int(charBytes)!
        let character = UnicodeScalar(number)!
        result += String(character)
    }

    print(result) // "Happy Birthday"
}

convertAscii(asciiStr: "7297112112121326610511411610410097121")

Converting String of ASCII character values to actual string in swift 2 (latest beta)

Your charArray is an array of String, and your stringArray is
an array of Character, so there seems to be something mixed-up.

Anyway, you can use the array of characters, slightly simplified to

let charArray = asciiArray.map { Character(UnicodeScalar(UInt32($0)!)) }

and then create a string from that array:

let string = String(charArray)
print(string)
// -86,-44,2191,14

Swift How to get an ASCII value from a character

You can't get it from the String but from a Character in a string, for instance

str.first?.asciiValue

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