如何在Swift中生成随机的字母数字字符串?
Swift 4.2更新
Swift 4.2在处理随机值和元素方面引入了重大改进。您可以在此处阅读有关这些改进的更多信息。这是减少到几行的方法:
func randomString(length: Int) -> String { let letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789" return String((0..<length).map{ _ in letters.randomElement()! }) }
Swift 3.0更新
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 }
原始答案:
func randomStringWithLength (len : Int) -> NSString { let letters : NSString = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789" var randomString : NSMutableString = NSMutableString(capacity: len) for (var i=0; i < len; i++){ var length = UInt32 (letters.length) var rand = arc4random_uniform(length) randomString.appendFormat("%C", letters.characterAtIndex(Int(rand))) } return randomString }