swift 单例的实现方法及实例

public class Game {  public var score = 0  public static let dafaultGame = Game()  private init(){  }  public func addscore(){    score += 10  }}

let game1 = Game.dafaultGamegame1.addscore()game1.scorelet game2 = Game.dafaultGamegame2.addscore()game2.score