Generate random alphanumeric string in Swift

Question

How can I generate a random alphanumeric string in Swift?

Answer 1

Here's a ready-to-use solution in Swiftier syntax. You can simply copy and paste it:

func randomAlphaNumericString(length: Int) -> String {
    let allowedChars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
    let allowedCharsCount = UInt32(allowedChars.characters.count)
    var randomString = ""

    for _ in 0 ..< length {
        let randomNum = Int(arc4random_uniform(allowedCharsCount))
        let randomIndex = allowedChars.index(allowedChars.startIndex, offsetBy: randomNum)
        let newCharacter = allowedChars[randomIndex]
        randomString += String(newCharacter)
    }

    return randomString
}

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If you prefer a Framework that also has some more handy features then feel free to checkout my project HandySwift. It also includes a beautiful solution for random alphanumeric strings:

String(randomWithLength: 8, allowedCharactersType: .alphaNumeric) // => "2TgM5sUG"