【Swift3】ランダムな英数字を生成する方法(桁数指定可)

本体

func randomString(length: Int) -> String {

    let letters : NSString = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
    let len = UInt32(letters.length)

    var randomString = ""

    for _ in 0 ..< length {
        let rand = arc4random_uniform(len)
        var nextChar = letters.character(at: Int(rand))
        randomString += NSString(characters: &nextChar, length: 1) as String
    }

    return randomString
}

使い方

let randomString = randomString(length: 10) // 10桁のランダムな英数字を生成
print(randomString)

参考

・Generate random alphanumeric string in Swift - Stack Overflow