Swift 将多个用户存储到一个活动-哪种技术？

我想将多个用户存储到一个活动中，如：

Play Nintendo
-> Rick
-> Peter
-> John

现在的情况是，我还可以进行多种活动，如：

Play Nintendo
-> Rick
-> Peter
-> John

Swim
-> John
-> Robert 

我的目标是将所有这些活动和依赖的用户放在一个（多维？）数组中，我可以将其永久保存在设备内存中

此外，设备用户应该能够在任何时候将用户添加到任何活动中

---

你能给我一个提示，我该如何处理这件事？我被困在空间中，希望得到任何提示。

您可以使用

NSUserDefaults

和

NSObject

-类保存数据

（我无法测试代码，因为缺少Xcode:-））

class Activity:NSObject {
    var activity:String!
    var users:[String]

    init(activity:String, users:[String]){
        self.activity = activity
        self.users = users
    }
}


class test:UIViewController {
    override func viewDidLoad() {
        var user = Activity(activity: "Play Nintendo", users: ["Ryan", "bill"])
        var activity = loadActivity("Play Nintendo")
    }

    //Load existing activity for a name
    func loadActivity(activityName:String)->Activity{

        if(NSUserDefaults.standardUserDefaults().valueForKey(activityName) != nil){
            let theActivity:Activity = NSUserDefaults.standardUserDefaults().valueForKey(activityName) as Activity
            return theActivity
        }else{
            var newActivity = Activity(activity: activityName, users: [])
            saveNewActivity(newActivity)
            return newActivity
        }
    }

    func saveNewActivity(activity:Activity){
        NSUserDefaults.standardUserDefaults().setValue(activity, forKey: activity.activity)
    }

    func addUserForActivity(activity:String, user:String){
        //Loads the activity with the users by using the activity as key
        var theActivities:Activity = NSUserDefaults.standardUserDefaults().valueForKey(activity) as Activity

        //append a new user to the activity
        theActivities.users.append(user)

        //save the activities in the userdefaults
        NSUserDefaults.standardUserDefaults().setValue(theActivities, forKey: activity)
    }
}