swift 在swift中创建所需长度的随机字母数字字符串

Posted 2021-05-19

//
//  Extensions.swift
//
//  Created by Harshad Kale on 1/23/16.
//

import Foundation

extension String {
    /**
        Create a random alphanumeric string of desired length
     
        - Parameter length: Desired length of the string to be generated
        - Returns: Random alphanumeric string of length `length:`
    */
    static func randomAlphaNumericString(length : Int) -> String {
        var characters = Array(48...57).map {String(UnicodeScalar($0))}
        characters.appendContentsOf(Array(65...90).map {String(UnicodeScalar($0))})
        characters.appendContentsOf(Array(97...122).map {String(UnicodeScalar($0))})
        var randomString = String(length)
        
        for (var i = 0; i < length; i++){
            let length = UInt32(characters.count)
            let randonIndex = Int(arc4random_uniform(length))
            randomString += characters[randonIndex]
        }
        return randomString
    }
}